"He was hit on the head with a spiked instrument"

Sir Harry Oakes was found with a cracked skull, caused, according to the post mortem report, by being hit repeatedly on the head. With what exactly, remains another mystery. An unidentified blunt instrument? A boat's winch lever? A conch shell? 

The human skull...
Public DomainThe human skull... - Credit: Skimsta

Bullets were even suggested by some, along with conspiracy theories about this being covered up.

There are also reports of four indentations on Sir Harry's skull, which does not support the gunshot wound theory... 

Meanwhile, despite the fire which had been started in the mansion, the burns on Sir Harry's body were thought not to have come from this. Another mystery.