I thought that also, but when the replay was held frozen on the frame where Andersen/Wilson both had their foot on the 18 yard box, I wasn't sure what exactly they were looking at. Then, when the ref was heading over to the monitor, the commentator mentioned "we understand the penalty will stand and it's been checked for a red card offence". WTF? This again raises the question of how was not sending the player off a clear and obvious error??
I can just imagine it now...fans chanting "f*ck VAR" and "VAR is shite" for 10 minutes, and the TV broadcast has to ironically turn off the pitchside microphones to block out the crowd noise so that the commentator isn't constantly saying "apologies for those of you who may have heard any offensive language"