Inigo definitely would've scolded Senku, were he the scolding type. But Inigo is well aware that he isn't, and besides - it seems that the other has already thoroughly understood why it's such a bad idea in the first place. And hopefully that'll keep him from repeating the same mistake in the future.

So he shakes his head, dropping the issue. Instead he knows there's something much more important here to ask.

"Did you learn anything from it?" That's why they were doing the experiment, right? To learn from the experience?