إِلَّا أَنْ يَتَجَاوَزَ الْمِيقَاتَ مِنْ غَيْرِ إِحْرَامٍ ثُمَّ يُحْرِمَ بِالْعُمْرَةِ وَالْحَجِّ فَيَلْزَمُهُ دَمٌ وَاحِدٌ.
Translation: Except when he passes the miqat without ihram and then enters ihram for both Umrah and Hajj: in that case one dam is due.
This is an express exception to the rule of two dams for a qarin. The miqat crossing is one occurrence, and this specific described case entails one dam.
Three elements are stated: the person crossed the miqat, lacked ihram at the crossing, and subsequently entered ihram for both Umrah and Hajj. The exact factual pattern matters.