The 40 time is irrelevant for TEs. Very few TEs ever run a route that takes them 40 yards. Apparently this guy is a sick blocker, has good hands, and can get off jams. That's what you want from your TE, especially if you have good WRs. And now that Buffalo has 2 good WRs, Pettigrew could be a good pick.
Of course, the Bills have so many needs besides TE, I could see them going defense in the first two rounds and not drafting a TE until the 3rd or 4th.