If you are worried that JC would answer a tweet which asked, "Does dragon breath pop invisibility" with simply quoting the rules definition of 'attack' again, and would still be unconvinced because the rules don't say what is not an 'attack' (because the book says what the rules are, and are under no expectation to say what they are not!), then instead ask this question:-
"The book says that if there is any doubt whether something is an 'attack', the rule is simple: it is an 'attack' if it involves an attack roll (or an explicit exception), does this mean that something that has no attack roll and no wording to specifically say that it counts as an 'attack' is not an 'attack'?