In my point, of course it's annoying but this thing happens in reverse continuously with both of these jobs, cops and criminals,
I don't think really it's a bug, but why there should be a rule about it, it's just enable to use by those 2 sides,
Maybe there's another solution rather than this uphill struggle with the firetrucks, just by reducing or even limiting the water flowing time to make you make you have a chance to run or shoot the truck till it blows up, in adding, make a cool down about it.