You have just said you don't know them so that means they don't know you. They don't know your not a tottal arsehole who's not going to start screaming at them for interfering or then cause trouble.
I dont no them but iv seen them in the hallway and said hi. I just dont think 20 mins of a baby crying warrants a visit from the police, possibly if it had gone on for an hour or so. But the fact the must have called the police after about 10 mins for them to get there so quick doea piss me off