There's no doubt that deer can learn to avoid the cameras. I think, in regards to the flash, its the shadows created by the light that spooks deer, not the light itself. I have, over the years, and where legal , shined many a flashlight on deer at night and observed their behavior. Most of the time, if they get jumpy, its not from my light, its from their own shadows or from tree branches or brushshadows casted by the light. Your results may vary, but these were mine.

Also, I think smell/scent plays an important factor that is being overlooked. I am not, nor will I ever be, convinced that a deer cannot smell the camera, or the owners scent left from placing or checking the camera.

Moving the camera every three days is probably the best advice I've heard when it comes to keeping deer on their toes and not spooking them with the camera, or allowing them to learn their location. Or just cover the entire property with cameras so deer cannot move without getting nailed. [8D]

Hunting pressure doesn't make a deer change it's home territory, so a bunch of cameras probably wouldn't either.