I'm not familiar with swim team or dive team protocol, so take what I have to say with a grain of salt... :tongue_smilie:
If it was mandatory that all team members arrive together, why weren't you notified of that when you made the arrangements?
If it was discovered later (after you had told the team parent of your plan) why didn't the team parent contact you?
I can tell you that if my child was forced to get into a vehicle without my consent, I would be LIVID...and the coach/team parent would definitely get an earful.