There were certainly the tells in 1964 that he’d go bad. Remember in 1974, how he couldn’t tell the time? Tripped him right up! Nothing got by Columbo:
“Paul Galesko is a famous photographer married to Frances, a nagging woman and a grumbler. Paul is in love with his assistant, Lorna, so he decides to stage a fatal abduction of his wife. Everything seems to go very well to Paul, and the police accept his version of the events, but Lt. Columbo has some doubt.”
https://www.imdb.com/title/tt0071348/
As everyone knows, only the good die young:
Born Richard Wayne Van Dyke
December 13, 1925 (age 98)