Well he did already promise to do it free of charge and I was a high school kid, still making car payments from my night job. I really didn't want to buy a new tire 
but you flat out lied to the guy.
i have a customer just dropped off his buick, for me to move the fuel gauge needle back to the right side of the pin. it's a 97. that era gm products used to have a tendency to have the gas gauge "jump" when you jump started the car. it would go beyond one of the travel limit pins, and then it's stuck. only way to make it right, is remove the cluster, and lift it over.
he tried insisting it happened when i changed the battery the other day. after he had it jumpstarted to bring it here. since i know that happens, i looked inside the car before i touched it. i saw the gauge there, noted it on the invoice. when he came to pick up the car, and i told him it was done, he went right to the car, and looked(as if he knew what had happened), then comes back in to me, trying to tell me i messed up his gas gauge. i told him it was like that(which it was), and he asked me how it got that way. i told him it happens when they're jumpstarted.
he tried to keep arguing with me(he thinks that because he's a retired electrical engineer, that he can out-smart me with electrical stuff on his car....this isn't the first bad dealing with this customer). it took me a few minutes to get the point across to him that i knew EXACTLY how it happened.
then he admitted that he tried jumping it 2x himself, which wouldn't get more than a rapid clicking from the car, so he called AAA....they jumped it for him. and yes, he IS paying me for removing the cluster to set it right.