Hi miss, sorry to hear about your "off".
Just to clarify, traction control (or ABS for that matter) is not designed to prevent tyres breaking grip on a loose surface on a bend- only in a straight line.
The mirror covers are indeed one of the first parts to touch. If you look closely they are fitted with small rubber "caps" on the end which are designed to be replaced in the event of a drop. Obviously they cannot prevent damage from a more severe accident.
Hope you got away without too much damage to yourself.
BP