There are a lot of armchair experts telling us (drivers) when we should and shouldn't press the REC button. No one except me can decide when and when not to press that red button. I will only press that button if its going to stop a human from being injured. Now that doesn't mean I'm never going to use it for a non human danger, if there is a herd of cattle on the line, I'm gonna hit that button, not to save the cattle but to stop anyone else hitting them. And no-one is going to come and tell me off for using it when I saw fit, as has already been alluded to, the worst possible scenario is that drivers have any doubt about pressing a REC button at the risk of a comeback.
Much like Bromley Boy I'm not hitting that button for a dog by itself. A dog alone on a single line, that'll get a normal priority call to the controlling box, a dog alone on a double (or more line), that'll probably get an urgent call, just in case an owner is nearby but I've not seen them and there is a risk they may arrive. However any situation where an person is on the line, that would get a REC call.