That doesn't matter, the UCI code considers all equipment that a rider or team possesses within the confines of the race area as to be part of the equipment covered by the rules, and every rider and team knows this.
The presence, within or on the margins of a cycling competition, of a bicycle
that does not comply with the provisions of article 1.3.010. The use by a
rider, within or on the margins of a cycling competition, of a bicycle
that does not comply with the provisions of article 1.3.010. All teams must
ensure that all their bicycles are in compliance with the provisions of article
1.3.010. Any presence of a bicycle that does not comply with the provisions of
article 1.3.010, within or on the margins of a cycling competition, constitutes
a technological fraud by the team and the rider.
No rider brings into a competition area any equipment that they do not intimately know and they are fully aware that the UCI is going to have access to look at it all. Her excuse that it was a friend's is about as sound as Sharapova's excuse about doping yesterday. Possessing the bike, bringing it into a competition area, mixing it with competition equipment... it makes no difference whether or not anyone proves it was "used" (by any definition), the rules were explicitly clear.