@SkepticalCat
I was wondering the same about the vegan contestant and how she feels about using non-vegan ingredients for the technical challenges.
She'll have known about it going in. There may even be non-technicals she has to relax her principles, eg I remember they had a signature Meat Pie once, and others where the alternative ingredient really doesn't work. Not sure I can imagine vegan choux or laminated pastry...
She may only have become a vegan recently so has used non-vegan products in baking before.