f_oneway doesn't work correctly with integer arrays.
I checked, I also get the same wrong result with scipy 0.13.3
@josef-pkt : The problem isn't exactly with integer arrays. The same works if dtype of the input arrays is changed from np.uint16 to np.uint32, probably because the former causes some values in the code to overflow outside the range 2**16 - 1.
2**16 - 1
BUG: make stats.f_oneway work with integer array input.