True, just saying that its not all that hard to proove his seizure was caused by the gif.
either way, we do know the sender sent it with ill intent (why else would you send a photo sensitive person a strobing gif with the words "you deserve to have a seizure"? Yes, you can troll with ill intent). Cyber stalking is a bit weird, but maybe that's how they could get a guaranteed charge since I think cyber stalking includes harassment / intend to harm over the internet.
Oh, here's the law. Seems to fit the law fine:
http://www.statutes.legis.state.tx.u...E.42.htm#42.07