These are the possible outcomes I can see:
Case 1: He testifies and makes a fool out of himself - bad publicity. Most JWs will not know what was actually said and can dismiss news articles as lies by Satan's media
Case 2: He testifies and nothing "damaging" is said - unaltered publicity. Same outcome as if he never testified.
Case 3: He testifies and smooth talks the RC - OK publicity. JWs nods along to his words and the watchtower (to the JWs) is absolved of any pedophile protection accusation(they are eager to swallow any explanation given by the GB).
Case 4: He flees the country - very bad publicity. Hard for JWs to explain away if they learn about it, maybe; he must have had his reasons etc...
Case 5: McClellan lets him go for compassionate reasons or otherwise - unaltered publicity. Same as if he was never called to testify.