Questions about bad blood between Sinclair and LonDi head - SPOILERS

From what I understand, Hobbs-Caine's motivation was that Sinclair has to pay the ransom and as he's personally liable, he'll be ruined. And so he does, no arguments there.

But then the sequence of how this happens doesnt make sense. Sinclair and the LonDi head have huge arguments - the head even says if Sinclair doesnt pay, he'll devote the rest of his life to ruining Sinclair. But then Sinclair leaks to the press, presumably to buy more time for the investigation. Wont that piss the LonDi head further? But then the LonDi head dies. Wont that work in Sinclair's favour? Instead why does LonDi still go ahead with the ransom? And when does Sinclair pay at all? Cant he just say no until the investigation is over, now that LonDi head is dead and no one will be devoting his life to ruining him? Instead he pays up and commits suicide. Doesnt make sense.