Would/should you really shut down one engine not having 100% established the cause of vibration when you had only just got airborne and were so close to landing? Looks like shades of the BMI crash on the A1 all over again to me.... close down a good engine then something untoward shuts down the other one.
I also read the pdf of the AAIB Report in full on Friday-Saturday and the crash seems a total mystery to me. Did the ACM bearings really give up after just a minute or two into this flight, with no previous anomalies in the previous flight? Was one engine shut down totally within a few seconds of the vibrations being noticed? Worrying stuff, to me