The bloke was quite clearly not an Owl who at every opportunity throughout the 90mins, found the need to laugh, clap and make smart comments at every bad reffing decision, missed chance etc...
I've very often been a neutral at a match but have never been silly enough to sit there slagging off the home team in the middle of their Kop.
So while standing up may have been a little petulant, there's 2 sides to it...