Following is a story i heard from R’ Mendel Aronow):

R’ Hillel was once visiting the Tzemach Tzedek. In honor of the illustrious guest, a bowl of cherries (strawberries?) – a delicacy at the time – was placed on the table. Both the Rebbe the Tzemach Tzedek and R’ Hillel made a brocho, and partook of the treat. However, while the Tzemach Tzedek ate them whole, R’ Hillel first opened each one and carefully inspected it for worms and bugs. Only after assuring himself of its kashrus, did he place it in his mouth. Some of the Chassidim, who were closely monitoring the visit of the famed chosid with the Rebbe, found the behavior of R’ Hillel an affront to the Tzemach Tzedek. As soon as R’ Hillel emerged from the room, he was accosted: “Hillel”, they demanded, “how could you act differently from the Rebbe in his presence? Are you perhaps more frum than the Rebbe?” “It is very simple”, R’ Hillel reassured them, “the Rebbe, being a true tzaddik, can be assured that he will not encounter anything objectionable, as the Possuk says “לא יאונה לצדיק כל און”. Therefore he has no need to be overly cautious. I, on the other hand, have no such protection; I, therefore, have to personally verify the appropriateness of anything I take into my mouth”.