This is because 'to hit' can of course mean "to punch someone" in English, and then 'ler' is the present tense of the Norwegian word for "to laugh". Put these words together and it made some amount of sense to me to imagine old "hit-laughs" as someone who hits people and then laughs at their pain, in other words a bully, a sadist, or otherwise a cruel villain.
One said that he was an extreme sexual sadist and was filled with lurid tales of his activities (and hinted at more), the sort of thing that pooping on Eva Braun would have been one of the more mentionable ones.
One said that he was completely asexual, and was in love with Germany, and only hung out with Eva (and eventually got married) to legitimise his appearance of being a German statesman.
One said he was extremely gay and had a lover that he maintained into The Great War.
In the light of current moral panics, I'm surprised there wasn't one claiming he was secretly trans or something