To state that Caesar's troops were carried away at Gergovia, or that they didn't hear the trumpets sounding the recall is putting too much trust on Caesar's relation of the event, I think.
I've been to Gergovia and I really can't see where and how someone could not have heard trumpets unless existed then a weird acoustic phenomenon.
The Romans may not have been carried away; they may just have followed the roman military doctrine of smashing through the center, exploiting holes in the enemy lines and offensive posture at all times and at all costs. They wefre led, as caesar writes, by several centurions and probably other officers such as signifieri, optiones and trumpets. Hence my doubts --I'm not the only one-- about the soldiers being "carried away".
Sometimes the "all offensive" tactics worked, sometimes they didn't and this time they didn't.
I suspect Casear never sounded the recall he is talking about in his book and that on the contrary he pressed his men on to the assault.
And yes, as much as I deplore it, it was a defeat.. Caesar wanted to take Gergovia; he didn't and lost a great number of soldiers.