And it gives the media a chance to print "he lies" since it's someone else saying it, and they're afraid of getting in trouble.
And it entices Donald to say something stupid like, "I don't lie, she lies. Everyone knows it" since that's what he's devolved into. Anyway then the paper can print that too.
That's been really the biggest issue with the media, the inability to just call out liars. And not just that, people that have been consistently wrong keep getting invited back to give their opinions.
None of the people that lied about Iraq WMD's for example should ever been given a platform again, but yet, there they are, pushing for the next conflict. Same with economics, everyone that said Obama was going to do a communism should be shunned forever.