Wow, I thought he died years ago being the reason why he was not in season 2.
Back in the day I was a kid and had a subscription to Dynamite Magazine, remember that? And they had a write up on the second season of Space: 1999 and they said Victor was supposed to be written out of the show by way of a heart attack to make room for the new shape shifting character of Maya.
I haven't seen it since it first aired and haven't rented any of the DVD's so I have no idea of they even filmed but but I remember expecting to see Victor die in the first episode of the second season. Maybe someone who has seen the DVD's know if it is mentioned in the commentary or in a special feature or something.
Oh look! I found the cover!