The most painful surprise while shaving

Yesterday I had the most shocking and painful experience while shaving (aside from an epic case of razor burn many years ago).

While testing a new tuck of Bic Astor blades I had this out-of-the-blue sharp pinch. The blade just decided to pluck a hair.

I was now completely awake and careful as careful can be. This had to be investigated.
Shaving proceeded smoothly for some time... then on the left side again: a hair was painfully plucked from my tender cheek.

Another man would have trashed the blade then and there, but we are here talking about a member of WickedEdge. I scientifically determined that it is only one side of the blade that causes the hair plucking. Not clear what the mechanism is. With my eyes I see no edge defects.

Any idea what is happening?
Have you had surprises like this?