@BCS Uhhh, wasn't it exactly the other way around? They were suiciding together, which was
his idea but she was going through with it for him (and considering she's nigh immortal she's giving up a
lot of life for him), and then right in the middle he changed his mind and, to save his life he grabbed her heel to pull himself upwards, then
stepped on her head, pushing her down to get a bit closer to the surface. Then he crawls out and apparently assumes she's dead, doesn't even look back let alone try to help her. So if there was
actual murder going on, it was by him against her.
Then later he actually pulls off the "lover's suicide" with some other girl. Good riddance, poor girl though.