Where are the reports that it was a brothel they raided at 4.30 in the morning and not some flat where a wanted man was? 
4.30am? - that's when the BiB generally go looking for those on the "Wanted/Missing" list if they have good enough info that the suspect will be there. The theory is that they'll be able to get in the premises and "hands on" with the suspect before s/he is awake and able to offer much resistance.
If they were going to raid an alleged brothel, they'd wait until it was entertaining clients before making a move.