My worst experience ever - about 3 years ago.
My pit man was a very seasoned racer (expert class). I'm running sportsman class - RC Pro State series race.
I'm running in third when my buddy (fellow driver) in second flames out. My pit man calls me in for fuel. I come in and my pit man is helping my buddies pit man get his car started.
I yell at him, and yell at him, he finally sees my car and fills it. He is right at the end of pit lane, drops my car it flames out. He has turned back around is trying to help re-start my buddies car again.
I'm now yelling as loud (a bunch of F-BOMBS) as I can for my pit man to get my car. He is looking around and cant see it. I had to let my car roll down the ramp 2 feet off the end let the others come out of pit lane. A by stander had to hand him my car.
After the race I asked what the hell were you doing? He said "I was helping get his car started, he was in second." I said "you are my pit man and when he flamed I was now in second!"
He said "OH!, you were in third?" I finished 8th...........