I accidentally pressed report spam on a post that wasn't spam. Is this a problem or I should not worry about it? Sometimes on a smartphone it's easy to press wrong buttons or the phone can register two presses in a row. Maybe there could be a confirmation asked after the report spam button?
You're fine. In truth, the spam report system is honestly pretty bunk. The button doesn't send any actual report that anybody reads, it just logs the fact that such-and-such user pressed it. After X number of users press it, the post is deleted. Doesn't matter how many times you press it for the same post, it won't do a thing unless it's pressed by multiple different accounts.