The OP didn't give any description or detail as to what sound he thought might be "abnormal". If it's the well-know whine of the ST engine then the shop didn't explain it was a normal sound. It's not much of a stretch to consider the shop may never have seen (let alone heard) an ST prior. More info is needed — if macmanus ever replies.
Agreed !! But if you listen to the video very closely, especially at the point they bring the camera down low, I think what the OP hears is the typical tapping of the clutch basket.
Many folks unfamiliar (including Honda dealers!) are not familiar with the sounds.