How On God's Green Earth Did This Ball Not Go In?

AZ Alkmaar plastered PEC Zwolle in the Dutch Cup today by a score of 5-0. However, due to some wicked backspin and an insanely precise smack off the crossbar and the possible imposition of dark magic, AZ forward Mats Seuntjins’s 15th-minute strike somehow was not one of those five goals:

To quote another famous AZ, this non-goal is rather unique.