The crime in this case is accessing software running on someone else's computer without their authorization. The "someone else" in this case vehemently objects to the access at issue. The burden of proof is on the prosecution, but their argument is compelling enough that it's the defendant who'd have to do the explaining.

No: you will not get convicted checking on your neighbor. Everybody involved in that fact pattern will believe that you at the time believed it was OK for you to peek into their house. Now change the fact pattern slightly: you're not a neighbor at all, but rather some random person walking down the street. A lot less clear, right?

Anyways that's what these cases are often about: the defendant's state of mind.

Note here that this is a Firebase app, so while it's super obvious to me that issuing an INSERT or UPDATE on a SQL database would cross a line, jiggling the JSON arguments to a Firebase API call to flip a boolean is less problematic, since that's how you test these things. The problem in the SQL case is that as soon as you're speaking SQL, you know you've game-overed the application; you stop there.