Everyone reacts differently to grief.  There is audio of Trump on a similiar call, and he sounded okay to me, not mean.  As for Johnson, I can't pass judgement on her feelings, it did upset the family and friends listening on speakerphone.  However, Trump's words as reported, were not awful, just awkward -- and I believe he meant well.  Again, everyone reacts differently to grief.

However, leaving aside the one call, in the rest of the Trump saga with Gold Star families, Puerto Rico, etc.  -- he doesn't help himself.  He needs to develop a thicker skin -- as his reactions to any negative opinion requires compassion, self-knowledge and a conscience.  He makes himself appear to lack all three.