This MOULIN episode looks like a COLUMBO scheme. It begins with the murderer matter, and everything besides that may lead to the crime. So we, the audience, already know who the bad guy is. And of course everybody waits to see how the lead cop will proceed to nail him.
Yes, that's pretty much like a Colombo episode. Paul Le Person is powerful as the boss who intends to kill his wife's lover before blaming her for the crime.