This is just my opinion based on speaking with 5 or 6 neurologists about cannabis use and epilepsy, my personal experience with epilepsy and many hours of research on the aforementioned subject.

If you have seizures you have epilepsy, seizure types, causes and triggers are very much an individual thing. There are very few if any cases of cannabis use causing seizures. Sometimes coming down from being drunk or high can lower your seizure threshold however, but moderation of use in therapeutic levels of cannabis lessen this effect. More than likely if he indeed did seize it was caused by something else and it was a coincidence that he was using cannabis at the time. Some studies indicate that using cannabis actually prevents damage to the brain during seizure episodes. Other studies indicate that therapeutic use of cannabis can even lower the likely hood of seizing at all.
It has been my experience that cannabis lessens the severity of my seizures and I recover faster (a few hours as opposed to a day or more). I also tolerate the pharmaceutical anti-epileptics side effects more easily while using cannabis.

My suggestion for ANYONE suffering any seizure like activity, anything even remotely similar to a seizure is to seek immediate medical attention! Do not worry if you have taken an illegal substance. Doctors are there for your health and safety not to call the cops for drug use.

A friend died several days ago from epilepsy and heart problems. Uncontrolled epilepsy can kill you