Initial reports from Reuters stated that Bay and his Transformers: Age of Extinction cast and crew were in Hong Kong, on their first day of shooting overseas, when two brothers approached the director, demanding $100,000HK (about $13,000 USD). As the discussion ensued, one of the brothers attacked Bay, and then attacked three police officers, before being placed under arrest. Also arrested were his brother, and a third companion.
The men are rumored to have been members of a Triad—a network of Chinese crime organizations, much like a Chinese mafia—seeking a "disturbance fee." Such fees had already been paid to local businesses that would likely be affected by filming. The case has been turned over to anti-triad detectives in Hong Kong.
While the Reuters report made no mention of home cooling units being used as weaponry, Bay's film publicist Gabriela Gutentag revealed that an air conditioning unit—unfortunately, not a Decepticon—was involved in a statement to The New York Times:
The production company did have a bizarre encounter with a man (allegedly under the influence of a narcotic substance) who was wielding an air conditioning unit as a weapon. The man, who had earlier accosted several other crew members, rushed onto the set in Quarry Bay and swung the air conditioning unit directly at Bay’s head. The director ducked and wrested the air conditioner from his attacker, preventing what could have been a serious accident.
Dramatic! Machines being used to attack humans. Who woulda thunk it?