Somehow, it figured that Gin had witnessed enough to cause trouble. Still, he hadn't interfered, and he'd have been more than capable of doing so.

"He didn't give us a choice," Kadaj said. "If I didn't kill him, he'd have killed me. Nnoitra just got caught up in things. I'd have been dead without his help."

Which didn't explain how it had started, or Kadaj's torturing of Orochimaru afterwards, but was, at least, a partial truth. Kadaj was trying to avoid saying everything, not so much because of Gin, but because of Nnoitra. He didn't want to reveal more than he had to.

But Gin was smarter than Kadaj was, and Kadaj knew it. If Gin wanted to know what had happened in any detail, and why, it probably wouldn't be wise for Kadaj to try and hide it from him.