[runjake]

I am completely unqualified to answer this question, but it seems to me the CEO should be handling this.

You, as a VP of Engineering handling this could put the CTO on major defense, as it'll make you look like you're vying for their job.

[headscientist]

Right, I've thought this too. I mentioned in another reply that, on the one hand, I appreciate the CEO giving me some time/space to figure out how to approach this delicately. On the other hand, I feel he should be providing more support to me in this scenario. How exactly though is kind of a good question.