It comes down to being a manager and managing your resources. With his overtime compensation BART could have hired 1.5 additional workers including the benefit load to do the work on regular time. How efficient is a worker doing manual labor after 40 hours, 60 hours, 80 hours?
It really depends on the individual. Some people are willing to work like dogs for 12 hours 7 days a week, while others just mail it in for their 40 hours/week. We really don't have any way of knowing whether this guy earned the money or not.
I don't like the tone of the article that implies this guy is doing something wrong.