I saw him turn his head and look back at Purdy, and then stick the ball out in front of himself. He was taunting him. I'm not the only one that saw that. If you don't see it, I do understand why, some others don't see it either, and if him taunting Purdy is ok with you, that's fine, it doesn't bother a lot of people now a days.
It wouldn't have bothered me for him to high step into the EZ, hold the ball out in front, or dance a jig in celebration. I think penalties for normal exuberant celebration are ridiculous, but taunting is over the line.