According to the officials, yes, yes he did.
Days later, in his weekly officiating video, NFL senior V.P. of officiating Dean Blandino explained why, exactly, Fisher should have been penalized.
"We talk about position, body position," Blandino explained, via PFT. "We talk about feet. If the blocker can maintain good feet and he can maintain position in front of the defender and if he can stay square to the defender and he can continue to move his feet, we're not gonna have a foul for holding. If the defender gets outside his feet and the blocker has to reach, now he reaches with his left arm across the body of the defender and he's gonna grab ... on the jersey. When we see that, now we have to look for restriction. Does he materially affect the defender's ability to get to the ball carrier? ...
"The other factor, we have a rip . . . technique," Blandino continued. "Where the defender's gonna bring his arm under the arm of the blocker, try to gain leverage, and get through to the quarterback. When there's a rip, there's no foul for holding unless the defender's feet are taken away. And you can see clearly the defender's feet are gonna be taken away as he's taken to the ground."
And while this may do little to convince skeptics, the reality is that this one play isn't the reason the Chiefs lost. Quarterback Alex Smith missed several opportunities for big plays. Here's one example:
The All 22 shot of Alex Smith abandoning a clean pocket as Tyreek Hill breaks wide open for a sure TD. pic.twitter.com/YM7vAsD0ud— Clay Wendler (@ClayWendler) January 16, 2017
Had Smith converted one or two of those big plays, there would have been no need for that game-typing two-point conversion in the first place.