Is AUTHOR wrong in the post ? POST : First time posting here. I hope my grammar and spelling errors won't make it a pain to read, as I am a french student.

So it all happened two days ago. We were about to be tested for our german oral expression. The problem is that about 90% of the school loathes german, but still take it over spanish because it may be useful in the future. It ends up in almost nobody being able to learn the language, as the french method to learn languages is shit (I still have no idea how I got that one godly english teacher, though). So, everyone was panicking because we were all gonna pass the test in two hours, and I had not even managed to learn my text yet. So did my classmates.

So, at lunchtime, I offered everyone to skip the class before german. It was an hour long class we have every other week where we learn to use our graphic calculators, as it's needed for our math exam at the end of the year.
The thing is that nobody likes that class, everyone is bored and we hadn't even seen the professor all day. So? What happened? I encouraged everyone to skip class and practice our exam together, because we were almost certain to all get a 3/20 or something like this oterwise, since we couldn't remember anything we learned the night before.

It happens, we skip class (we're only 14, but still), even the two students with above 16/20 grades in languages and who are just really good students overall. Everyone studies or chats and we get the test. We didn't get the grades yet, but that's not important.

Then, the next day, the principal comes in with the teacher during our first period and proceeds to ask where we were at x time of day instead of in class. I proceeded to say before everyone else that we skipped class to study for our oral expression and that I was the one who offered to do so in the first place.

The entire class ended up getting 2 hours of detention and everyone's parents got a message via the school's grade viewing system with the explanation.

Luckily, my classmates didn't turn me down and said they took part too since they agreed to skip class, but that was useless. Every single parent started emailing my mom, talking about how their kid is gonna fail his math exam at the end of the year (we're 12 graders) and that I am a stupid kid who doesn't care about school. This isn't true, I'm working hard and have a good reputation as a student, but I really don't know where to put myself as I got every single one of the students in my class grounded, even the really smart ones, except myself, because my grades weren't inflicted and that I skipped to study, so my parents just told me to not do it again.
But really, I have no idea what to think of now...

Am I the asshole?