Factual error: Rakman Habib's driver's license shows that he lives in "Beverly Hills CA 91605." That is the ZIP code for North Hollywood, not Beverly Hills.
Factual error: Columbo gives another detective $5 to go to the gun range for him. Technically, that is a bribe and it would cost both Columbo and the other detective their badges.
Factual error: Columbo asks for a red wine. His host orders a Beaujolais but the butler brings a Bordeaux. Beaujolais is from Burgundy, not Bordeaux. (01:18:40)
Factual error: Santini murders Jerome using a revolver with a silencer. Although this is one of the oldest Hollywood tropes, a silencer (properly called a suppressor) does not reduce a gunshot to a whisper; it only cuts the noise to about 110 dB, which is still very loud. In addition, suppressors do not work at all on revolvers, because most of the noise is generated in the gap between the cylinder and the barrel.
Factual error: All LAPD officers must re-qualify with their weapons multiple times a year. If indeed Columbo could not "hit the target," as he says to another detective, he would never have made it through the police academy, much less have become a detective and have been promoted to sergeant and eventually to lieutenant.