Rezo would like to say that he's normally quite observant, and that he only bumps into other people at the same rate that sighted people do. It's just that he's still getting used to being out and about again without chains and besides, Ziel was being unnaturally still and quiet.

All this is to excuse the simple fact that Rezo, while he was trying to look for herbs, has accidentally poked Ziel in the thigh with the end of the long cane he's using to navigate.

"Oh-"

After stifling his initial startle, Rezo's quick to offer an apologetic "Pardon me."