Underneath the radar,
The most logical thing to do in that case would be to continue toward your destination, work out a PNR to a suitable alternate with a comfortable margin. If your destination is socked in at your PNR - go to your alternate. PIC 101. I'm only speculating but it looks like thats what they did in this case. Diverted to MQL only to find enroute, it was now fogged in. Very little time to make a decision to go back to ADL where you know you're landing below minima. Kudos to the crew. Safe outcome!