I am not implying this happened here, but we don't know what's the story behind this guy being fired. There are remote chances that the company tried to be vicious with him after letting him go. It happened many times before.
This could be similar situation to the one where A starts beating B, out of nowhere, and then A calls cops before B had a chance to do so. Cops show up and A says: "look at my bruises" and B gets arrested.
The problem is people making bad tips to the police; if the intent is malicious, they should be prosecuted.
Sounds like the problem here was the employer, not the cops. Heck, it sounds like they didn't even have a warrant to search - they asked if they could come in and the person said yes.
The worst I can possibly think of to accuse the cops with in this case is showing up with too many people. One or two uniformed officers was all that was necessary.
[1] http://www.youtube.com/watch?feature=player_detailpage&v=7I0...