Again, related to his eyes. I noticed two weird things in particular:
1) Suteguma's left eye seems to squint at a crucial moment:
Imgur Link.
It happened in the poker game when he lost that one round, and it may have happened two times in this Dotty game, although the evidence is a bit weak.
2) Baku, while trying to "read" Suteguma in the round 2 of Dotty (Chapter 228), turned his back to him twice, and each time afterwards he looked at Suteguma, trying to get a reaction. Was he trying to prevent Suteguma from seeing his own face? Or trying to trigger something else...? The second time he turned back is when he got the 'small reaction' from Suteguma.
I'm not too sure what to think of it all. It might be that his facial agnosia is partial in one eye or something, or that when his eye is strained, his ability isn't working for that one brief moment..?