A good review Frank and very timely indeed. It will certainly lend credance to Sam's cheffing or cook's skills, depending on which argument one agrees with, and also to all the info that has been passed on through the videos that others may wish to rubbish, but i for one value, enjoy and appreciate.
As for that underlying taste, which didn't appeal to your taste buds, you will indeed have to wait for the book before you get an inclin as to what caused it. Totally agree with your deductions and would be looking to the base or the oil.
It always amazes me when you detect a taste but you just can put your finger on exactly what ingredient is causing it

Bloody infuriating in fact ;D