User blog comment:PUNCHURPREGNANT/Gray and Silver Predictions/@comment-135.0.27.38-20140111155246/@comment-7418318-20140111161627

He only was close to Angel for a very short time (not to mention that he was somewhat preocupied with the battle and his motion sickness at the time) and then alot of time passed until he saw Yukino.

Gray on the other hand is around him all the time, so it'd be easy for him to memorize his scent.