It's both possible and likely probable.What would you generally expect someone's 40 time to be with his vertical and broad jump numbers? Assuming you both are saying he should have been faster with those numbers, but correct me if I'm wrong. Possible or probable that he didn't spend enough time working on proper running form before the combine?
Look--- speed is a gift. But even kids without speed can be taught better technique to shave a few hundredths of a second off. A good get off is key. Honestly we all knew the guys wasn't blazing fast, but 4.79 40 is pedestrian for a WR. I honestly would have said he was a low to mid 4.6 guy. With 33 inch vert--- there's "some" explosiveness---
Is there a video of him running that someone has a link to?