>>96701161
When people have limited cognitive resources, they generalize.
Being that a DM is not an experienced social leader and has an already quite difficult job in running the game, it is common for them to over generalize
I don't think there was anything wrong with this specific instance of you getting out your phone, but it makes sense that a busy dm would be upset at you for breaking the rules when he left you alone
It is alot of effort to need to coral people like that, especially friends

You should probably apologise to him, he was (likely) stressed and, to prevent these cognitive load issues in future, try not playing dnd

Also don't use your phone too much, it will rot your brain