Friday issue: The difference of opinion issue

Today W fell asleep about 15 minutes before the lunch was ready so me and J got a meal all to our selves. Oh how great you all think but think again. We ended up ruining the lunch by getting into a fight. I can't really remember how the conversation got started but the fight started with something like this (I'm paraphrasing because I do not have a photographic memory):
Me: School is very important and I'm going to make sure W knows that and that he doesn't cut school.
J: Oh, good thing I didn't finish what I was about to say before that...
Me: What were you going to say?
J: Oh well... I was going to say that if he's tired it's OK if he skips first period to stay at home to sleep because I read that sleep is very important to teenagers. And as long as he tells me it's fine, him and me can have a nice morning at home and go for a coffee together and then I'll drive* him to work.
Me: No that is so not OK. So you're telling me that as long as he tells you he can cut class? That's the same as saying "oh I know he'll drink anyways so I'd rather he does it with me" that's insanity! If he's so tired he can go to bed earlier not sleep in and skip school. You're so just saying that because you think it'll be nice for you to be the "cool" dad that lets him cut class so you can have coffee together, that's what the weekends are for! ...
J: Well yes but I don't think it's that bad.
Me: ... just think about the lesson you'll be teaching him! School is not important and if you're tired just don't do what you're supposed to!
J: He'll have all the time in the world to do what he's supposed to later.
Me: Well how will he know he has to when you're teaching him he doesn't?
J: He'll know! Besides school is not that important you can skip classes here and there it doesn't make any difference!
Me: OMG it does too! I had less than 2 percent absence from school when I was a kid and I had great grades and you skipped all the time and barely finished school! It matters!
J: Oh... yeah, well... maybe...
Me: Besides teaching him to show up on time when he has to is an important lesson to know for when he's older and has to be at work on time.
J: Oh no school doesn't teach you timekeeping. I'm always on time and I wasn't punctual for school but Dicky is always late and he was always in school
Me: I know he's always late to come see us but is he always late for work cause that's what we're talking about?
J: Well I don't know... maybe not for work.
Me: Well then it works.

This went on and on for the entire meal and I got very angry. Obviously I think I'm right and he's oh so very wrong but I would still want your opinions on the subject and on how you deal with differences of opinion!

I also wanted to add that I'm not all against pulling him out of school for a day to spend some quality time with him but letting him skip classes in the morning so he can sleep in just sounds wrong.

*it's is now necessary to know that J doesn't have his license and he has no concrete plans on getting it. He took his theoretical test about 4 years ago but has yet to drive the car or schedule an appointment for his practical test.