What do you mean by "disturb"?
Temperature can always impact the fate of a reaction. Light is sort of redundant, since in flash photolysis you are blasting your sample with light anyway. I suppose it's possible that if the sample was exposed to light of a different wavelength, this could impact things. Oxygen is frequently a problem because it reacts with triplet states that are commonly generated during flash photolysis. Reaction with oxygen is limited by the diffusion rate of oxygen in solution, typically on the order of 1 microsecond.