The props would have gone to fine pitch to try to maintain rpm when the power failed even if the pitch controls were set for cruise rpm.
The important part is the psychology. What prevented him from looking further and finding the empty tanks? It seems this aircraft was fitted with digital fuel guages. Are the analogue guages simpler to read than digital ones. Would the empty tank be more obvious with an analogue guage reading empty than a digital one with numbers? The analogue guage indicates unambiguously that the tank is empty merely by the position of the pointer. There is no need to read numbers. I always found an analogue clock was much easier to use for timing approach patterns as you could just look at the angle of the pointer and just forget about the numbers.
Or maybe this situation was just too overwhelming and resulted in tunnel vision.
Whatever it was I feel sorry for the PIC. This sort of occurence is devastating. I'm sure he would have wanted to prevent this. I wish him well.