I agree, it doesn't look like she's having an epileptic fit. And it also looks like she whopped the cop one as they fell down the stairs. On the other hand, I have to agree with mc1variant that from the footage it's hard to see why he felt the need to hit her so hard and so repeatedly in swift succession. It does not look like a case of a single blow and then wait to see how she responds. Sadly, the policeman's own words do him no favours. His words and the images combined seem to indicate that he intended to hurt her rather than simply control her behaviour. Whether because of a supposed racist motive or because he wanted to get his own back for being hurt as they fell down the stairs or simply out of frustration at her behaviour and that of others like her, I couldn't say.