OK .. most likely scenario .. DJK pressured Morgan into letting him into the flat, then he hung around like a bad smell, then he tried to crack onto Morgan at which point Morgan and he began to struggle, and somehow in that scenario DJK pulled Morgan's pants off him, became enraged, pulled out a knife he had in his satchel and stabbed Morgan to death in a fury. JMO.
DK carrying a knife, I guess if one is hooking up with a stranger you want to be prepared.
MH may have had abit too much booze, DK a tense & perhaps paranoid nutter, MH might have non intentionally put DK down in some way, made some kind of joke,
Something that MH had said might have sparked the nutter off, even though MH had his pants off, does not mean he had had sex with DK