Yes, that was the play I saw. It was a tough play for no. 17, and a nice play call and route call for SH.
17 was locked on a bigger receiver, maybe a TE (I couldn't see the number), at 4 yards depth. The depth tells me that it was a bigger/slower receiver, or 17 would have been lined up a bit deeper.
SH was in trips right (3 receivers), and sent a 4th receiver (no. 10 who caught the TD) in motion from the left side. The safety followed 10 across the field from fairly deep.
Yes, they were in man coverage.
When 10 started to go past 17's receiver to the outside, 17 did the right thing and switched men, so that the safety could take the then inside receiver, wouldn't have to continue further, and the 2 Griz defenders wouldn't get in each other's way.
17 took an awkward step to his left to get better position on where 10 was and was going, as the switch occurred. He was a bit off balance and not in good position to cover a slant route (to his inside) as the step and momentum took him outside, nor did he have enough depth for a receiver running in motion and with some forward momentum when he turned up field.
17 should have had more depth, but he couldn't because of where he was lined up on his receiver. I suppose he had one more chance to backpedal faster from his 4 yard depth. That would be my only suggestion or criticism. But again, his momentum due to his step to get wider had him going in the wrong direction, and the motion receiver had momentum to propel him downfield faster.
Due to the blitz, there was no linebacker to block the view of the qb and get in way of the throw to help the defender. A slant without a linebacker help is hard to defend.
I doubt that 17 got much criticism from the coaches for the play.
Irish probably knows more than I do. I recall a specific secondary post he made a year ago, which showed me that he knew what he was talking about. I have no info on the play from coaches or anyone else.