One of the fans was wearing a T-shirt that said "I have the body of a god" in big letters. Then it had a small picture of Buddha underneath.
The Palace fans chanted "You're Welsh, and you know you are" at the Bristol fans. That seems pretty random; it's clearly not true, and if it was true (e.g. when Palace plays Cardiff) then it wouldn't be taken as an insult.
Another chant was "Stand up, if you love Palace, stand up, if you love Palace" (etc.). This earned a rebuttal from other Palace supporters: a few of the guys in the wheelchair area shouted back "Are you taking the piss?"
At one point in the game, a Bristol player kicked the ball in the air, and a Palace player ducked out of the way so it was successfully passed to the Bristol player behind him. (The alternative would have been to head it.) When even the hardcore Palace fans are groaning, that's not a good sign! Putting that in perspective, they will normally applaud when someone aims for the goal but the ball bounces off the crossbar; as Raymond Chen said (The economics of soccer penalty kicks), "it means that the opposing goalie didn't even have to be there".
Bristol scored just after half-time, putting them 1-0 up. Five minutes before the end of the game, the score was still 1-0, so it was pretty obvious that Palace were going to lose, and the fans were starting to drift away. One of the Palace players had the ball near the Bristol goal, but there was no way he could score from there. Then a Bristol player fouled him; even I could see that he tripped the Palace player up. This meant that Palace got a penalty, and they scored. So, leaving aside the ethical issues of fouling, this was pretty poor tactics: Bristol were winning, and then this guy pretty much gave away the game. Muppet.
I don't think I'll ever be a football fan, but at times like this I can start to see the appeal: the energy levels from the Palace fans soared, and there really was an attitude of "Hey, we can actually win this game!" When I mentioned running the other day, I said I'd go flat out at the end of a race, and there was a similar issue here: it made sense for Palace to pile on the pressure in the hope of getting a second goal. When the tannoy announced 5 minutes of extra time, the crowd were all enthusiastic about that; the implication was that this would benefit them a lot more than Bristol. Unfortunately, Bristol then scored again, so Palace wound up losing. Still, it was a dramatic end to the game.
More generally, it's quite common for football players to "take a dive", i.e. pretend to be injured when there's nothing wrong with them, so that they can get a penalty or have a player from the opposing team sent off. However, this doesn't always go according to plan, so I've seen a few cases where someone is lying on the ground and nobody else is paying any attention, so the game carries on without them. In a situation like this, the "injured" player has a bit of a dilemma:
a) If they get back up and carry on playing, that makes it blatantly obvious that they were faking the injury.
b) If they carry on lying there, they feel a bit stupid, and may get trodden on.
It's quite entertaining to watch their faces as they try to figure a way out; the standard solution is that they'll struggle manfully to their feet and then limp back to the game before making a miraculous recovery.