Meanings of hallucinate when in English

Weren't people said to hallucinate when they were on the brink of death?

Dr Ellis, however, said it was very rare for people to hallucinate when given midazolam through their nose, and sexual hallucinations were very unusual.

He thought he was hallucinating when he opened his eyes.

I must've been hallucinating when I saw his resting palm press too hard and go right through.

According to a post on Mountain RU, Gukov was "on the verge" and hallucinating when rescued from the perch where he lay.

I wasn't hallucinating when I shot Pel, and I didn't kill him and his team to cover up some mistake I made while stoned.