I looked up Hank for grins, and Google pulled up a post that explained this play perfectly. Recommended reading for anyone ITT.
https://weeklyspiral.com/2021/04/26/hank-concept/
Like look at this picture, and then go re-watch the routes our receivers were running. Identical.
The website explains how the QB should read it.
So in Dak's progression
1. Even numbers pre-snap. 3 standup defenders on the strong side against his trips, 2 standup defenders against his 2 guys on the weak side, Warner is dead middle.
2. Post-snap, Warner "attaches" to the sit on the weak side, I guess. It's more like Dak looked to the weak side first, then Warner read his eyes + Pollard, and then just started flying.
3. The CB is glued to Ferguson on the curl, to the point where I don't know if he's pressing Fergy or if Fergy is blocking him.
4. And off we go to the flat.
I think the execution was fine... the Niners were just ready for it.
I think the only way they could have avoided it is with a pre-snap motion check, to see if the defense is in man. This play is a zone beater, and the hitches+flat don't work against across the board man (which SF was running). If Dak saw man, then he could have audibled to a run or a man-beater concept.