I hope that wasn't the case.I would think that if it were obvious to the judge that the attorneys were eliminating everyone but mothers, that he or she would override Voir Dire- or at least keep viable options open, to include at least one man.
Then again, some people (both male or female) seek to avid jury duty during Voir Dire. There were at least four very opinionated people on the potential jury that talked themselves into being removed.
In a child negligence case, I would definitely want at least some parents in the jury! I believe that they're looking at more than just the chromosomal makeup of a "jury of your peers."