I think the recent threads on spinning have been wonderful. I find
them a great help to focusing on such an important issue.

Somewhere in my dark student-pilot experiences I was shown that
coordinated flight, with the yaw string kept carefully in the middle,
does not guarantee against spin entry. As I recall, it was pointed
out to me that even with the string in the middle, in a steep turn the
inside wing is flying at a higher angle of attack than is the outer
wing. If a stall is induced in such a steep turn the inside wing is
likely to stall before the outside wing and thus will have higher drag
than the outer wing and the glider will likely fall off over the
inside wing. If confusion or inadequate skill or distraction get in
the way of an immediate recovery the higher drag of the inside,
falling wing may initiate an autorotation and possible spin entry.

Does this seem like a real possibility?

In any case, it instilled in me the knowledge that the yaw string is
not an indicator of the relative angles of attack on the two wings.