I take no credit for this idea but i saw it as a comment on a sawyer7mage video today and i thought i would share. In chapter 604 it seems as though obito was momentarily able to see through kakashi's sharingan and even witnessed him piercing rin with his Raikiri.
well in the comment it stated that possibly besides the fact to conserve chakra since he is a non uchiha kakashi might have covered up his eye so that tobi/obito could not see kakashi's daily activities and leak information. I believe that kakashi knew about this since that day(that obito came and saw rin die) and also evidence of this is when the K11 with yamato and kakashi meet Tobi (while Sasuke is fighting Itachi) Kakashi seems a little weird like he is thinking really hard and contemplating something. it is believable since kakashi is a smart guy he could have felt something was going on. anyway thank you for bearing with me and have a nice day.
:hypertobi:
well in the comment it stated that possibly besides the fact to conserve chakra since he is a non uchiha kakashi might have covered up his eye so that tobi/obito could not see kakashi's daily activities and leak information. I believe that kakashi knew about this since that day(that obito came and saw rin die) and also evidence of this is when the K11 with yamato and kakashi meet Tobi (while Sasuke is fighting Itachi) Kakashi seems a little weird like he is thinking really hard and contemplating something. it is believable since kakashi is a smart guy he could have felt something was going on. anyway thank you for bearing with me and have a nice day.