I thought it was a great idea. It was his way of settling an issue without playing favorites between two parents that he deemed of equal value to the children. Not mentioned in this article is that both parents agreed that the coin toss was probably the best solution to the impasse.
The pants dropping incident was way out of line. He had every right (and obligation) to seek to have proof of the injury and to see the wound.
However, he should not have allowed things to get to the point where the woman partially disrobed. This is especially true given that he was aware of her mental instability. True, she wanted to take her pants down, but she was not of sound mind in that decision. He could have insisted on a female bailiff taking a localized Polaroid in a private room, or better yet, the woman could have been given shorts to change into. The wound was on her thigh.
Also not mentioned in this article is the fact that the woman had a history of being a "cutter", a self-mutilation by use of razor blades. There had also been a previous incident where she claimed she was abused, but later admitted that she had created the wounds herself. Further, the cuts on her thigh were razor thin with perfectly straight exact parallel lines, her usual method of cutting, and not at all like knife wounds of an altercation.
So the judge did the right thing by proving the likelihood that the cuts were self-inflicted. He also did the right thing by denying the woman's request to bar the father from contact with his children. I'm glad he stood up to the false allegations of abuse.
Too bad he abused her in his own way in the process of getting the right result.