49ers Notebook: Shanahan discusses penalty that negated Ambry Thomas touchdown; Arik Armstead unhappy with Jags O-lineman; Jags humbled by 49ers

The 49ers came back from their bye week with a vengeance on Sunday, blowing out the Jaguars 34-3 at EverBank Stadium in Jacksonville. The win snapped a three-game losing streak for the 49ers while breaking a five-game winning streak for the Jaguars, and it also re-established the 49ers as one of the teams to beat in the NFL.

The bye week turned out to be just what the doctor ordered for the 49ers after losses to the Cleveland Browns, Minnesota Vikings and Cincinnati Bengals in Weeks 6, 7, and 8.

"Bye week was huge," running back Christian McCaffrey said after the win Sunday. "Think everybody needed a little mental, emotional, and physical rest."

The 49ers had one of their best overall performances of the season, led by 296 passing yards and three touchdowns from quarterback Brock Purdy and four takeaways and five sacks from the defense. Meanwhile, the Jaguars were held to 221 total yards and were given an unexpected wake-up call after five consecutive victories.

"This definitely was a humbling experience today," Jaguars head coach Doug Pederson said Sunday.

There's plenty to talk about from Sunday's game, even with everything we've posted on 49ers Webzone to this point (links below). In this version of 49ers Notebook, we have some words from head coach Kyle Shanahan about one of the game's strangest moments, plus we find out why defensive lineman Arik Armstead was upset with one of the Jaguars' offensive linemen. Let's get into that and more.

See also: 49ers disappointed over missed opportunity for McCaffrey | Shanahan calls Brock Purdy TD throw 'one of the worst decisions he's made' | Kyle Shanahan, 49ers appreciated Steve Wilks' sideline presence | Deebo Samuel, Trent Williams make impactful returns | Chase Young fits in nicely, makes impact in 49ers debut vs. Jaguars

Lesson learned the hard way

Cornerback Ambry Thomas should have had one of the game's top highlights when he pried the ball loose from wide receiver Christian Kirk, recovered the fumble, then ran the length of the field for the touchdown. Instead, Thomas was only given a forced fumble and fumble recovery while the 49ers were stuck taking over at their own 19-yard line because the touchdown was called back when 49ers players and coaches entered the field from the sideline during Thomas's return.

One of the coaches on the field was Kyle Shanahan, who told reporters after the game why he and others left the sideline.

"I was mad at myself, and I thought the play was over," Shanahan said. "We couldn't see, and everyone jumped up. And so when that happens, you're getting out there to start to congratulate people coming back, and they're not coming back to congratulate us. They're running back at us."

It was an understandable mistake considering how the play unfolded. Thomas was on the ground for a moment after recovering the fumble, then got up and started running the other way. There was confusion over whether or not he was down, which led the 49ers to enter the field. The 49ers wound up not losing any points because their offense scored on the ensuing possession, but it was a learning experience nonetheless.

"We know the rule, definitely. We know you can't go on the field," Shanahan said. "I personally thought the play was over. They ran right by us, and it was very unfortunate. It was a good learning experience for our team. We do show that stuff, but it was short lived because we ended up scoring. So we can live with it, but a good learning example for us."

In addition, it was a big moment for Thomas, who was given time at outside corner on Sunday while Deommodore Lenoir slid inside to the nickel spot. Thomas has had his ups and downs during his 49ers career, but he's been making strides in recent weeks, according to linebacker Fred Warner.

"Confidence. And that's truly the difference right now," Warner said of Thomas. "I feel like he's been getting better and better every week, just waiting for his opportunity, and I think he made the most of it today. Obviously made that big play on the sideline, but I think he just competed his tail off all week and then leading into today."

Easy pickings

Warner notched his third interception of the season and the seventh of his career on Sunday, and it's unlikely he'll get many interception opportunities easier than the one that came his way against the Jaguars.

While under pressure, Jaguars quarterback Trevor Lawrence threw the ball right to Warner, who wasn't near any Jaguars players when he made the catch. Warner joked about the play when asked about it after the game.

"Yeah, that was pretty tough, man," Warner said. "I have to say, Trevor Lawrence, he throws a good ball. A nice spiral to me. That's my bad. I shouldn't have said that."

Warner's pick came with the 49ers up 27-3 and was the fourth and final takeaway of the game for the defense.

"I felt like all game I'd been kind of jumping the check down when we were in zone coverage, and so later in the game, kind of got to have a situation," Warner said. "I sunk back a little bit in that dig window and he just threw it."

Unhappy Armstead

Arik Armstead left Sunday's game for a short time after hurting his shin, and afterwards he directed some frustration towards a Jaguars offensive lineman, which reportedly was guard Brandon Scherff. Armstead's description of the incident made it sound more malicious than it first seemed.

"I didn't take one in the shin," Armstead said. "He tripped me, kicked me in my knee, and kind of messed up my day."

Armstead returned to the game and did not report any lasting effects from the incident. He was still clearly unhappy about the whole thing, however.

"I didn't know what happened," Armstead said. "I had a lot of respect for him, but tripping me, kicking me in my knee, could have got seriously hurt. Just a dirty play."

Feeling a little pressure

Brock Purdy may not have shown it on the field, but after the game he admitted there was a slight bit of pressure on him Sunday after the 49ers lost the past three games.

Purdy threw five interceptions in those games, which were the first three regular season games he lost as the 49ers' starting quarterback. He told reporters the losing streak weighed on him somewhat but was still able to play loose and put together a solid performance.

"I guess a little bit," Purdy said. "When you lose games in the NFL, it's like there's a standard, especially with this organization. We all demand a lot out of ourselves. And so I was more feeling the pressure just within myself, like, man, I need to play better because of how I've played in the past.

"And so that's where I was at with it. But I came into this game with a clear mindset of, man, I got dudes around me, got a great defense, be smart with the ball and make plays sort of play free in terms of cutting it loose, but also playing within the scheme and being smart with the ball. So that's where I was at and got to keep playing like that, move forward."

On the flip side was Lawrence, who had his worst game of the season with 185 yards and two interceptions on 17-of-29 passing. He'll head into the coming week on a decidedly different note than Purdy.

"You've got to feel the pain and embarrassment of today," Lawrence said Sunday. "That's what it is. It's terrible. One of the worst games I've probably played in my career. So I feel that and I take responsibility for that. We couldn't do anything right today. But you've got to flush it too. It sucks but the reality is a 31-point loss -- and that's crazy to say -- but a 31-point loss is the same as a three-point loss. We lost today and we've got to move on. We're the same team we were five hours ago."