Only In Australia 4 - Bin Man Headstand

An 18-year-old named John gets his head stuck in a rubbish bin while trying to retrieve his phone, which was thrown in by a friend. Firefighters rescue him using an air-powered hacksaw. John reflects on the incident, humorously noting he'll aim to get stuck in something cleaner next time.

How did John's friends contribute to his predicament?

What lesson did John claim to have learned from this incident?