Perhaps...
"Ahithophel the Gilonite. The desertion of David by Ahithophel is in every way remarkable, even if he were Bathsheba's grandfather. (see note on 2Sa 11:3) For he was far too subtle a man to have joined the conspiracy unless he bad felt reasonably sure that it would be successful. Successful it would have been had his advice been followed; but so correctly did he estimate the result if David were allowed time to gather his friends, that, when his counsel was rejected, he withdrew immediately to Giloh, and committed suicide. Still if the revolt had been successful, it would have involved, if not the death of Bathsheba, yet certainly that of her sons, and the exclusion of Ahithophel's great-grandchildren from the throne. "
(Pulpit Commentary)