There must be more to this story.
A medical professional would not put anything into the mouth of a patient during a seizure.
I see many similar stories from European football leagues and online opinion pieces in recent times which gives the practice "repetition credibility" which makes people believe it is true.
Epilepsy peak authorities the word over agree on 2 key points in the case of a seizure:
DO NOT try to restrain the victim
DO NOT put anything in the victims mouth It is not possible to swallow your own tongue.
Time the seizure and, when it has subsided enough, roll the victim onto their side.