That sounds like the usual USCCB spin.
It is really sad how much your hate blinds you to the truth.
http://www.sspx.ca/Documents/Bishop-Williamson/December1-1997.htm
Here is a report from the time. There doesn't appear to be anything about abuse.
Q: What happened in the Seminary last Spring?
A: A talented but proud young Argentinian priest [Carlos Urrutigoity] who had been a Seminary professor at Winona for three and a half years, decided that the moment had come to break with the Society of St. Pius X and form his own society, starting with one fellow professor and two seminarians who walked out with him.
Q: But did this priest walk out, or was he told to leave?
A: As soon as it became clear that he had for some time, from within the Seminary, been secretly planning his own society, he was told to report in short order to the Superior General in Switzerland. When he refused, he was told within 24 hours to leave the Seminary which he had been subverting from within by his intention — ingenuously disavowed — to take with him as many Society priests and seminarians as possible.