Justice Elizabeth Bennett ordered that the man be added as a "party" to the B.C. government's appeal of a scathing July decision.
Four months ago, B.C. Supreme Court Justice Paul Walker ruled that the Ministry of Children and Family Development demonstrated "reckless disregard" when it accused the mother of being mentally ill.
The ministry apprehended the woman's four young children.
A social worker allowed the father unsupervised visits to the kids while they were in foster care.
The ministry maintained in court that the mother fabricated sexual-abuse allegations. Walker, however, ruled that the ministry's decision to provide the father with unsupervised access led to the oldest child being sexually abused.
Walker's ruling also accused a senior ministry official of "highly inappropriate" conduct. This included phoning the Vancouver Police Department's sexual-offences unit to "disparage" the mother's motives, mental health, and truthfulness.
The B.C. Supreme Court ruling caused an uproar in the B.C. legislature and was widely covered in the media.
In her recent B.C. Court of Appeal ruling, Bennett stated that the father may "argue errors in relation to the findings against him personally". In addition, he may make arguments that support the position of the B.C. government in its appeal.
Bennett also ruled that none of the identities of the parties can be disclosed.