"Speaking from experience, you don't stay dead." He didn't know any other way to put it. He's seen people die and come back to life. Even staying by Jeff's and Wave's sides until they woken up after he found them for dead. They had woken up after the twenty-four hour mark, but that rule had long since changed.
"Suicide is permanent." But that wasn't how they lost Lara Croft, she was a casualty to war. The enemy had created a weapon designed to make deaths permanent and Lara had fell victim to that... so he was told and gathered from the network since he had been in a coma for most of the war.