He was seriously injured in a traffic collision while filming a stunt taxi chase scene near Bangkok, at approximately 3 a.m. on December 17, 2010 (local time). He was doubling for
Ed Helms in
The Hangover Part II (2011) when his head smashed into a truck, leaving him with a huge gash over the right side of his head and flesh torn from his skull. His head suffered critical brain damage and he was put into a medically induced coma. Just a month after the accident, he came out of his coma. The shots of McLean in the moments before the crash were actually used in the final cut of the film.