A crow washed the walnut I gave to them

I have two crows outside. They sometimes watch me and I give them walnuts when I see them.

I left half a walnut in three pieces, one of the crows grabbed all the pieces, didn't swallow, dropped them in the water bowl which is also in the balcony. Took them back, put again and again. Made into more pieces, and took again and left. The other crow collected the small pieces from the water bowl and left. I just ate orange and maybe they smelled it on the walnut and wanted to get rid of the smell.

Should I wash my hands before giving them food? :) I have given them walnuts before and this is the first time they put it in water