There is a lot of difference between an Elitist Player and a Veteran player.
In the example you use, a Elitist will assume that everyone knows the fight and charge in without asking if everyone knows what to do, while a veteran will ask the group just to be sure.
As another example, an Elitist can't be bothered helping out new players and will just run with people they know are geared and skilled while a veteran will help new players out and doesn't mind running some older content occasionally to assist newcomers.
I think the prime example of an elitist player though is linking loot from an all guild raid in global.