Tennant Paid Late Fees Without 3 Day Notice

[Kevin Breslin]

A tenant paid the late fee even thought I didn't send a three day notice. Can that come back to bite me? 

They are frequently late and sometimes tell me they are going to be late and I waved the fee but I charged the fee in last month but didn't this month. This is in a non-rent control California city.

I know it's paranoid but....