Cannot possibly

We leave for Portugal within the week. I need to present a paper and Steve is coming with me.

As I was preparing for my talk, I reread the paper that had been accepted and had a few things I just didn't agree with. I went back to earlier versions of the paper to see if I used to understand, but had lost it. No, I had clearly told the student what had to be said. He is a PhD student and he is first author, so I trusted him to fix it. He is Nigerian, but has excellent writing skills.

In two places, he said that you "cannot possibly" find a better solution. The truth is that the solution is approximate, likely a good one, but is not guaranteed to be the best. Come to find out he thought the "possibly" in "cannot possibly" weakened it. ARGGGG!! Wish me luck explaining "cannot possibly". Hopefully, no one will have read the paper before my talk.