You would only be plunged into precipitated withdrawal if you were physically dependant upon codeine. Would you/they normally suffer from withdrawal symptoms if you/they didn't take codeine? If so, then taking buprenorphine could be a bad idea. Precipitated withdrawal is not really any different from normal withdrawal, except it hits all at once at full intensity rather than coming on gradually as it would usually do. I highly doubt you could reverse it by taking shitloads of codeine due to the ceiling effect.