They could theoretically revoke precheck for doing this, but my guess is they won't because it is a believable accident (just like people leave them in their bag all the time) and given that the sign warning about firearms mentions that even that is just a five year suspension, not permanent, my guess is they wouldn't even bother for an harmless item.

I've never done that yet I've never had any trouble finding water past security or even on a plane?!