People post pictures with people thinking they are other people on the Internet all the time. There was the girl who thought she met Arian Foster and got called out on it, there was the time Jonathan Cyprien thought he met George W. Bush. It happens, because people are stupid.
We found this one particularly funny though.
The picture is by Chris Parrish, a world champion water skier, and the picture is still up on Instagram. He says he's at the VMAC, which is the Seahawks' training facility, the Virginia Mason Athletic Center. So he would have reason to believe that he might run into Pete Carroll.
That is not Pete Carroll. This is Pete Carroll:
(Joe Nicholson, USA Today Sports)
This is the person you thought was Pete Carroll:
That is not Pete Carroll even a little bit. They have the same hair color, but this man is shorter and heavier than Pete Carroll, and, uh, is just generally not Pete Carroll.