I knew Father Kevin Robinson at the seminary about 25 years ago; ordained SSPX. Due to the infiltration of Novus Ordo priests into SSPX, a relative of mine used to look up all their priests in Cor Unum to make sure they were ordained SSPX. Otherwise he would inquire about a conditional ordination. Sometimes priests are "secretly" ordained conditionally, which never made sense; I guess it's OK to appease the conscience of the priest but the stupid lay people have to just shut up and take whichever doubtful priest SSPX might throw at them.
Having Novus Ordo "priests" operate in SSPX chapels was one of the biggest reasons The Nine originally split off ... a Fr. / Mr. Stark in particular.