Not aiming to refute your doubt of his seizure, but a big enough drinker can have a seizure while having a blood alcohol content high enough to make you or me seem drunk. Alcohol really downregulates GABA receptors and to a degree proportionate to the amount habitually drunk. So a seizure is possible. He puked daily after awakening, according to Nikki, he was hiding bottles, and, judging from livestreams, he was extremely drunk, blacking out, and passing out, so I'm thinking he was pretty severe.
Panic attack and anxiety is a kind of chicken/egg thing with withdrawal seizures; shitting yourself with anxiety over getting tossed in jail totes could lead to a seizure. In detox, the really heavy drinkers get titrated down with more benzodiazepines for longer—it's not a cookie-cutter protocol exactly because you can still seize while nominally drunk or on a too-small dose of benzos.
What I doubt more is that he did anything about the seizure. He probably just hopped on the bus. Like Harry Angstrom, he just runs from accountability.