Often times in the NFL it is hard to decipher a play on tape. I like to think I know the x's and o's of football (especially on defense) but NFL coordinators get paid big bucks for a reason. They design things to confuse the smartest of quarterbacks. This is such a play. I will do my best, but understand I have limited knowledge on why and how.
Late in the 2nd quarter, the Bucs were tasked with holding off a final drive from the Seahawks to go up by more than 7. They backed Seattle up to a 3rd and 14 (very long) which is an obvious passing down if the 'Hawks are looking to actually pick up the first. Often times HC's don't take the chance and run a draw or a screen pass (the safe move) but Mora decides to be aggresssive, which I can appreciate.
Pre-Snap: The 'Hawks are in a Shotgun formation with Trips Right and an offset back (Justin Forsett) to the right of Matt Hasselbeck. I also want to point out that before the snap you can see Hasselbeck staring in the direction of Ronde Barber and Tanard Jackson (this is important)
The Bucs are showing blitz with Geno Hayes and Barrett Ruud. Both Tackles (Hovan and Wilkerson) are in a 3 technique (outside should of the guard) which is extremely wide. Someone (I think It's Crowder but it's hard to tell) is also standing up. Here's the kicker, Ronder Barber is lined up directly next to Tanard Jackson shading the middle - strong side of the field. Why? Matt Hasselbeck is clearly trying to figure out the same answer. Some of the possible coverages out of this set-up could be a robber (1 over top, 1 underneath) with Ronder and Jackson in man coverage. A double team...or a zone blitz.
Play: Immediately after the ball is snapped, Ruud pulls away (I honestly didn't think he did a great job of disguising his intentions before the snap) and heads to the flats and underneath 3 different WR. This cuts off any option of going short to a hitch route or an out route or something. I have no idea what the WR ran, but Hasselbecks options ran dry, quickly. Unknown DL drops back into a seemingly curl coverage (essentially a LB drop 5+ yard and curls it off inside). Hence "Zone" Blitz. Hayes starts to blitz, but is manned up on Forsett. When Forsett comes out of the backfield, Hayes must follow. Jackson jumps the snap and blitzes from the outside and from Hasselbecks throwing shoulder. Stylez gets a great rush, but trips up just slightly. However, it's enough to force MH to run backwards and not towards the sideline. Jackson is right up in MH grill causing him to throw off his back foot on a dump off to Forsett.
The coverage is essentially a cover 4 with flats coverage by Ruud. Hovan doesn't get touched because of the screen being set-up and yet still gets nowhere near the quarterback. He starts to make the right move (which is to follow the play and not get sucked in by the screen) yet he hesitates. He's not in a position to blow up the screen anymore and now he is nowhere near the QB to make MH adjust. If you make a mistake, make it 100%. Hovan makes it at about 70%. He barely makes it past the LOS by the time the ball is thrown. Wilkserson gets block pretty decently, but stays with the play. He cuts off Forsetts route and gets his hands up to tip the ball. Hayes, because he pulled off of his blitz is in a perfect place to make an interception. He makes a great grab, and manages to hang on to it.
Result is Interception turned into 3 points.