Judge Evelyn Arcaya of Branch 144 made the announcement during the hearing of the case, which mediamen were not allowed to cover.
She issued no statement explaining her decision.
Lawyer Raymund Palad of the defense said Arcaya may have inhibited herself for personal reasons and they are in no position to question the same.
"Apparently the inhibition was due to the desire of the judge to forestall any doubt that she will be biased for the prosecution. We cant do anything, it is the right of the judge to voluntarily inhibit," he told newsmen.
The rebellion case against members of the RSM and ASG was originally raffled off to the sala of branch 146 Judge Encarnacion Moya but was later transferred to a family court because one of the accused was found to be a minor. Michael Punongbayan