Tri Star Ford

My 2006 Ford Freestyle had less than 3000 miles and the tires were worn. (My brother is a senior master Ford mechanic, but lived 4 hours away) He told me the tow was out and they will fix it under warranty and would replace the tires. Sure enough the Tri-Star fixed the tow and gave me the paper work to prove it. I said what about the tires, weren't they worn pretty badly? He said the mechanic said they were fine. I hadn't previously checked very well, but said OK. I drove a mile down the road and something told me to check. So in the Sear parking lot I had checked and I had the belts showing on two of the tires!! I went back and told the service writer and he said I would need to speak with the Service manager. He was in a meeting though. I went home and he did call me. I told him the story and he asked what would make me happy. I said Ford should replace these tires free. The car is new and the tow was out, i did nothing wrong. He offered a 50/50 split. Again I repeated this isn't something I did to the car. He said he would call me back. He did. He said they would replace them 100% under warranty. In the end the Manager did the right thing, but I cannot trust them to work on my vehicle. If I cannot trust a mechanic to be honest about something so obvious, what would they hide when something isn't so obvious?