Not a medical person, but learned a lot from a relative's illness:
If the event was a seizure (evidently not clear from the report) -- not only can epilepsy first occur at any stage of life, as already noted ...
But also, there are quite a lot of causes that can lead to seizures that look like epilepsy. Diagnosis can be very difficult (and often, the cause of seizure is not determined). It is diagnostically useful to see an EEG during the seizure (or failing that, as soon as possible afterward); obviously this is often not available.