These packages are noteworthy in that neither actually brought an extra rusher. Rather, defensive coordinator Vic Koenning was able to manufacture pressure with four rushers, retaining a full seven coverage players on each play.
The first package involves a corner blitz from the Ram position with a three-deep zone behind it. This is similar to a standard fire zone (five pass rushers with three deep coverage) but retains a fourth defender in the short to intermediate zones, taking away the backside route combination that might otherwise have been a pressure outlet.
The Sam linebacker runs with the seam route down the middle, while the corner and safety are able to take away the smash combination on the bottom. The deep corner to the short side is able to read the receiver's inside release and play more aggressively since there is no deep threat—this reflects improvement, as the secondary seems to better understand their pattern-matching principles than they did earlier in the year.
In the absence of pressure, the best Savage could hope for here would be for his tight end to recognize the coverage and sit down in the curl zone over the middle. Jeff Schoettmer is actually a little too much over the top here on the tight end; given the deep safety, I'd prefer the linebacker to be in more of a trail technique (around the red box in the below picture) to take away the curl here. The tight end makes a bit of a mistake by not sitting down here as he should be Savage's first look against cover 3.
Savage's next look was to his slot receiver, who should sit down in the curl zone in front of the safety, a common adjustment for the slot on a smash concept against cover three—see diagram 2 and explanation here).
Brandon Ellerbe (circled above) takes away that option, however, by recognizing the concept and splitting the difference between the bottom two receivers—again reflecting improved understanding of the pattern-reading concepts taught by the UNC defensive staff.
Note Ellerbe's open hips and eyes through the inside receiver to the quarterback in the above photo. Ellerbe's fundamentally sound coverage gives Terry Shankle just enough time to beat the right tackle with his quickness and get a drive-ending sack. Carolina got another sack out of the same pressure package later in the game as well.
The second pressure package involved more disguise, as Carolina showed blitz to the strong side but again only brought four, with a tackle-end twist on the weak side designed to take advantage of Pittsburgh's protection sliding to the bluffed blitz on the strong side.
Kareem Martin and Tim Jackson are able to occupy the guard and the center by slanting hard to the left, while Darius Lipford twists inside to the "A" gap between the guard and center on the opposite side. (Martin and Jackson's responsibility is not to rush here but to keep blockers off of Lipford.) The key here, however, is that Bandit Norkeithus Otis has been able to occupy the left tackle with his bluffed blitz, leaving the left guard one-on-two with Lipford and blitzing safety Darius Rankin.
By dropping, Otis also takes away the hot receiver, making him twice as effective as he might have been had he actually rushed. Lipford goes unblocked for an easy sack, also forcing a key fumble deep in Pitt territory. Lipford may get the credit here, but this turnover was the result of excellent team defense, with each player doing his job to set Lipford up for the big play.