Could be several reasons actually.
They can be coincidence, pilot error, causation by weather, et cetera.
Unless they can establish that both choppers were downed by mechanical failure it really doesn't make much sense.
Plus, traditionally companies, militaries, nations, buy a lot of one or two types of airframe and will fly those.
So if you have two crashes in 2 months and they happen to both be....... Eurocopter Dauphins, then that's probably more coincidence than anything.