["Regrets" is perhaps not the right word to describe the things Neo has been writing down. That implies emotion he simply doesn't have, after all. It's Sonic's clarification that gets him to pause, head canted slightly to the side before he corrects it. He wasn't expecting his organic counterpart to actually admit to having regrets, even if they are Eggman's fault.]

So you regret not defeating him faster.

[...that's not what sonic said, but okay.]

You should know better than to toy with him. For his many faults, he is still a technical genius; it's only a matter of time until he finds a way to outsmart you.

[...Ugh, but why even bother going to bat for Eggman when he was so quick to discard him? Even now, Neo Metal Sonic holds no loyalty to Eggman or his Empire. He cast that aside to focus on his primary goal - and even then he still failed. What does it say about him, a product of Eggman's genius, that even with the perfect plan - unmarred by Eggman's bumbling - he still lost?]