While I commend the diner for doing the free lunches to first responders, I wouldn't agree with the expecting premium treatment as a result.
We used to do the police department IT work at cost (materials) per the manager, with the idea that they'd reciprocate on tickets and such. They did not reciprocate, by any stretch of the imagination. Even when they were getting this free service, they were belligerant, complained about having to wait their turn, etc. They did abuse this benefit, having us work for free on their personal computers, their family's computers, and their friends' computers. When that manager was demoted, I was put in charge. I ended the policy, which caused the police to complain to corporate. The previous manager was fired.
If I am ever called to the carpet, there is no quid pro quo. I expect the king treatment, and think everyone should get the king treatment. Where I said I would do something, I did it. I always did a bit extra. I don't give special treatment, or owe anyone special treatment. Our clients get timely, professional service, and most of them think they're our only client. Similarly, if I'm caught speeding, for example, I expect to get a ticket. Not harassed. No special treatment. Just a professional job. I haven't had to deal much with fires. I really only deal with the firefighters on the radio, although one of our clients does training for firefighters.