Ummm I have to question that. Welker runs away from DBs. Westercamp not so much. I don't know when or where Welker's 40 time is from, but he's certainly much faster than that now. I also would have to see Westercamp run a 4.5 at the combine to believe he runs a 4.5.
Welker ran away from DBs out of his breaks; it's not like he was running away from CBs on verts. Unreal quickness, but I trust the 40 time.