not sure if it's been said, but you are also watching with lag on your end. what you are seeing is not quite what the players are seeing. you are seeing your PS3's interpretation of other people's PS3's interpretation.
that can't be very accurate.
Im not stating its terrible players all the time, but when I spectate I witness so many errors, simple ones, things that you as a player would never do. But it is what it is,
I think it's different when you aren't actually playing- you aren't as stressed, the player you're spectating maybe focused on something else other than the game, or the person playing may have other goals during the game.
I remember spectating a game where the guy would get killed without shooting back and then fight his way back to the spot where he got killed and shoot the guy who originally shot him- I chalked it up to him trying to get his Revenge Kills for that particular gun. Not my type of gameplay, but whatever floats his boat.
How do you spectate on purpose.. just not choose a weapon??
Yes, the game throws you into a ongoing game, do nothing, hit select and then choose the player you want to spectate.
Or just press circle, that will take you out of the menu & put you in spectator mode with someone on your team.