Then again, he doesn’t seem particularly suicidal, he clearly didn’t write the note, they specifically used the words “took ill”, and if he had intended to commit suicide, then would he not have done it in his bedroom? He knocked over the table, struggled up the stairs, drew the curtains and collapsed into bed. I think it was the culmination of a disease that killed him, but that’s just a theory.

He could have downed a cup of arsenic. The symptoms include vomiting blood and going into a coma. Would also explain the note and the awkwardness if it was on purpose.