Mmhce,
There is fairly well documented evidence of synchronicity of hair cycles due to a wide range of exposures (e.g., minoxidil, excessive elongation of the anagen cycle, pregnancy, etc.). All of these, and others, are posible mechanisms for hairs simultaneoulsy entering a telegen phase, thus one would appear to experience a result simular to what would appear to be telogen effluvium.
That is my opinon.