This is something that seems to be a commonly held notion, that Thais in general have 'mai pen rai' and will avoid all conflicts and whatnot. This isn't necessarily true. I was in a taxi once and it gave a mild ding to a car in the next lane in the middle of a busy Bangkok street. They both got out and the other driver was all attitude and was angry, and the taxi driver started yelling too. Thankfully a cop came by but I was afraid they were going to go at it. I think Thais like anyone else in the world won't necessarily avoid conflict.