to expect coach drivers not to smoke

[GoEngland]

Background: DD has just returned from a school day trip and has told me that they had to wait outside the coach whilst the driver finished smoking inside the coach. As the DC in question are 12+ they did ask why he was smoking and the teachers told him that they had special ventilation .
AIBU to expect better from teachers/school, like refusing to get on the coach.

I have written to the school via email and will wait for a reply. I can't contact the coach company directly as it is not one of the usual local ones and DD is not clear as to exactly what the company name was. I also think that it is not correct for me to contact them without all the facts.
If I feel that it is necessary after I have all the facts then I will write to them.
Maybe I'll post my letter on here first so that it is grammatically correct

I won't be posting a AIBU on school trips and I value the contributions of teachers. I addition 3 of my family are/were teachers.