Hi Heath Cozens,
did you yet find a solution to the flicker problem with the 5D shooting PAL in 60Hz environments though setting the shutter to 1/60?
I’m asking because I encountered the same problem this January shooting in New York. Much of the ambient lighting (not only fluorescents, but energy saving bulbs, some street lights) showed flicker which I couldn’t stop by any exposure time (the best behaviour I found with 1/40 (strangely enough), second best was 1/60). There were no issues whatsoever with my own litepanels sources (which was to be expected).
There also were no issues shooting with the C300 at 1/60.
Cheers,
Frank (based in Berlin, Germany, which is PAL and 1/50)