hi nick
i have read just about every single book about john cassavetes and there was never any comments about his appearance on columbo. there is a lot about peter and their friendship...but no references to columbo.

according to the columbo phile book there were many actors who have stated that they loved their experience of working on the show...theodore bikel from bye-bye sky high said 'the whole experience was a lot of fun' and that 'it was a pleasure to do a columbo'.....ricardo montalban from a matter of honor said 'i have very fond memories of that show..i did so many guest shots. very few of them stand out. that one stands out.' ....patrick mcgoohan from dawn's early light said 'it was a very happy experience'...robert conrad from exercise in fatality said he was thrilled with the whole experience....vincent price from lovely but lethal said 'i loved the show, so i was very pleased to be asked to be on it.