I've been the poor schmo carrying the pager. (Government job: Didn't get paid to carry the pager, but, if I got called in, was paid for a minimum of 2 hours regardless of how long I was there and the time was either OT or part of my 40 hours.) I'm currently a volunteer EMT in my local FD and have many friends who are career firefighters. The lawyer is *SO* off-base with his analogy. Paid FFs are paid for their time in station. They are not paid for the small (depending on location) percentage of time that they are off saving the world. They're paid to train, watch TV, train some more, sleep, train just a bit more, and -- yeah -- respond when the tones go off.
As a volunteer, I carry a pager. If it goes off (EMS-side), I respond if I can. If I can't, someone else has it covered. I put in my 40 for The Man. Then I put in another 10-15/wk because I want to. My brothers who volunteer at my station and are career down the road do the exact same thing. I get paid for when I'm ON-DUTY. They get paid for when they're ON-DUTY. For me, on-duty is sitting at my desk coding. For them, on-duty is either available-in-quarters, available-in-district, training, or on the scene. Their 40 is a bit different than mine. The point, though, is that duty hours are duty hours.