Caution: Murder Can Be Hazardous to Your Health - S10-E2
Continuity mistake: When Sheba the dog scratches Anders' car her claws are on the glass and the top of the metal part of the door, above the character line. In the photo that Columbo shows, the scratches go much further down the door.
Columbo and the Murder of a Rock Star - S10-E3
Factual error: They talk about Wednesday as day of the murder. On the other hand, we see a speeding ticket with 3-11-91. In 1991, March 11 was a Monday and November 3 was a Sunday, so whichever way the date is written the day is wrong. (01:17:53)
Columbo and the Murder of a Rock Star - S10-E3
Factual error: Champagne corks have a metal cap between the cork and the wire cage. (They can be seen when both Creighton and Columbo open bottles.) When Creighton injects the chloral hydrate into the champagne, he does not have the difficulty he should have getting through the metal. The needle does not come out damaged as it should, and it did not go far enough into the cork to put the liquid into the champagne-it would get lost in the cork itself.
Answer: In the show, he was already a Lieutenant. A promotion would put him in the next rank up, which for the L.A.P.D. would be Captain. However, some of a Captain's duties would be overseeing other officers and ensuring they're compliant with policies, regulations, and standards. It would also most likely take him out of the field. This is something Columbo has no desire for as he rarely goes to police HQ's. Nor does he show interest in compliance and standards (for example, not going to his semi-annual evaluation at the firing range). However, he could still be assigned to a higher pay grade based on expertise, which is a form of promotion that does not include rank advancement. This would be going from Lieutenant I to Lieutenant II. I don't believe in the show it's ever started what his pay grade is. Although, in s02e01 (I believe) he mentions making $11K a year. Whether or not this was a true statement on his part, if you could find pay scale information for an LAPD Lieutenant in the 70's, it could give you an idea of his pay grade.
Bishop73