Oh no, he was very clearly mad. Just not the sort of madness that gave the slightest indication that he'd deliberately cause harm to anyone (accidentally causing harm by talking people into things, on the other hand...).

ahahah, sorry, that was an unexpected response.

So maybe that's what happened? He talked the journalist into something and later saw that she had died because of that, probably also causing harm to the submarine?, then panic'ed and told lies to the police.

I met him at a conference where he talked. Very charismatic person with a strong passion for his projects. Very friendly and openminded about ideas from anybody, but obviously also eccentric.

I would definitely have gone on a tour of that submarine with him.

Madsen, not madness.