Nope.
Sasha Siemel lived until 1970. Died in Green Lane, PA at the age of ripe old age of 80. His last guide trip was in 1968.
There’s a museum started by him in Green Lane.
Who am I thinking of? I only know Sasha Siemel through Peter Capstick's book and I remember him discussing a jaguar spear hunter who was killed in one of these encounters (which is hardly surprising).