Yes, but it doesn't work. That could easily happen on the canon chain during quiet periods.
How long does the quiet periods usually last? If I find out that the chain I accepted have some proportion of stakes suddenly disapear for two days, I'll check it again. Late, but still objective.
More importantly, in PoAS, miners are working fulltime with accumulated stakes. If you don't want the real miners suddenly stop working , which is too obvious, you have to buy the accounts of those working miners. I can't figure out how to purchase that yet.