Funnily enough, those are exactly the actions of a 'few idiots' that everyone connected to Liverpool FC have attempted to portray the attack on the City team bus as being. The truth, which should be obvious even to you, is that the two incidents are worlds apart, and only somebody with a point to prove and a limited sense of perspective - like the person who tweeted that, for instance - would attempt to show otherwise. As Ric said, that incident was obviously spontaneous, and the idiots responsible were swiftly arrested. The attack on City's team bus at anfield, by contrast, was conducted by several hundred people. Crucially the incident at Wembley wasn't connived at by the club and the police, and didn't involve an attack on the first team coach.
Interestingly, the attack on the United supporters coach was brought to a very swift end by the police swiftly arresting those responsible. Interesting to think that the Merseyside police might have nipped the attack on the City bus in the bud by acting in the same way, but they just stood and watched and did fuck all to prevent the attack that was unfolding in front of them.
So no, I don't think it is hypocritical at all to complain long and loud about Liverpool's behaviour, including the behaviour of the supporters, the club and the police. I do think however that anyone who thinks the two situations are in any way comparable is a bit of a wanker, and an even bigger wanker if they think that what happened in the video you posted is 'the exact same thing' as what happened to the City team coach.