In cover 4, as the diagram depicts, the WCB (Joseph) played up on the receiver (Boldin). On Cover 8, Joseph would play off-man.
The MO (Sharpton) played the weak hook and took on the receiver going to his area (the RB)
The SAM (Barwin) and the MIKE (Cushing) were in zone match on the #2 and #3.
Barwin followed the widest (FB Leach), Cushing dropped back but failed to follow the TE.
No matter what, the SS Manning needs to read a little better.
As the QB made more than a 5-step drop, Manning should get back immediately (he was about a couple of steps late).
That is how I saw it.
The whole sequence can be found here: