It sounds to me like your son was feeling very anxious and not knowing how to communicate that, just as most people and most especially people of the male persuasion, he jumped down your throat instead.
I really like the way you stood up for yourself and insisted he treat you the way you wish to be treated, that was awesome! Honestly, I've seen sooooo many parents, typically mothers though, who allow their teens to speak to them in absolutely disgraceful ways! So well done!
Okay back to late to practice... in the moment your best bet is to do exactly what you did. Later on though, have a chat about what was going on with him at the time and don't let him mumble how he hates to be late. He needs to dig deeper and identify what was making him feel so out of sorts that he thought talking to you that way was okay to do. This chat needs to be calm calm calm. Best to be done when you're driving and he knows you can't see his face but he can't walk away. The car is the BEST place to talk to kids to get them to dig deep and open up.
As far as his, "OMG You're so strict!" goes, you can pat yourself on the back because if a parent of teen isnt hearing that at least once per month, you're doing it wrong. That's a general rule kind of thing, every kid is different and some kids are very content without pushing boundaries.
It's directed at you because of a few reasons and you can decide which one you like best.
1. Your husband doesn't enforce boundaries so your son doesn't push back.
2. Your husband has already smacked your son enough that your son doesn't push around him.
3. Your husband isn't involved enough to be in the position of enforcing boundaries.
4. Your the safe parent with whom he can be his emotional self and that means the nasty emotional self as well as the needy emotional self.
5. Your son does mouth off to his father but his father doesn't react to it so it's not a big deal to either of them.
Thank you so much for this post. I will have a chat with him after his practice. I never do this, so thank you very much, I didn't even think bringing it up again would be helpful but what you're saying makes so much sense.
And reasons 1, 4, and 5 apply to our situation. It's very frustrating because my intense kid (who does run anxious) seems to do best with boundaries in all ways, has since he was an infant, except with his dad. He genuinely likes my husband more and is really close to him, and my husband does not enforce boundaries with him at all. I've stood up to my husband about this too, it has been an issue for us. But it's genuinely not in him, and I can't force him to discipline. If my son did his screaming, yelling thing, my husband might say quietly "C'mon, you don't need to do that." And that's it. Every time.
But I think the "safe" part with me is that he wants to save face with my husband. He gets embarassed because sometimes my husband will say something totally non-PC like "you're being a baby." But no consequence.