You might try reading what Trump actually said rather than what state-controlled media says he said.
https://sharylattkisson.com/fact-check-the-washington-post-on-donald-trump-and-john-mccain/
I have read Attkisson’s account of the media and it’s the sole reason for throwing this mud back in their faces.
No one likes to dress down a POW who suffered but McCain himself allows the myth to be perpetuated, He could do the honorable thing and step forward to say “I was not a hero” but he relishes in the limelight of the hero myth the media have created for him. The man has no honor inside him to do the right thing or at least in this case he will not step forward.