This is unfortunate and (understandably), most customers want to fault the technician when this takes place. During service, however, the cartridge that determines whether a faucet is definitively on or off is not touched. What can happen is that air rushing out of a new set of filters through the faucet can damage the seal(s) inside the faucet and cause a drip. The solution to this is to replace the cartridge inside the faucet. Contact Watermart for details.