It is funny because I was re-reading the manga and maybe you should take a look at the page 4 to 5 (4) in chapter 242.
Maybe he DID use sage mode over there. Kishi is known to hide minor details but show just a little bit to keep people wondering. If you look at his eyes in comparison to the page before, it has slightly darker edges... And it is in the right angle where you can't really see the shape of his eye stones...
Edit: Like he was trying to copy the look of j-mans eyes or give it a little of his feel.. It is funny to notice this now because this was before we knew about sage mode but it might be nothing ;P