How do people that support Trump justify his insulting of John McCain?

I was discussing this on another q with one of the Jellies.

All the time, Trump supporters can justify mostly anything he says or does. Calling women “horse face,” making fun of people’s weight, making fun of a reporter having Cerebral Palsy, talking about grabbing women by the pussy – so many things, so many justifications and so much defense. Trump supporters will say they like that he has no filter. OK, but how do Trump supporters justify and defend him saying John McCain was “not a hero?” John McCain, decorated war hero, who spent 5 years (more than 5 years actually) as a Prisoner of War. John McCain, who, when the people holding him captive found out who he was (who his father was), offered him the chance to leave the prison and return to the US, yet he refused, wanting to stay along with his fellow prisoners until all were freed.

Please explain how John McCain can be called “not a hero” by Trump and how that can be defended by Trump supporters.

Not that this has been discussed as being a possible reason why Trump lost the Presidential vote in Arizona, John McCain’s home state.