It is possible (and is actually happened in the past) that someone can frame someone for being a scammer without spending any BTC.

This happened to ndnh (formerly ndnhc) in 2015. Someone extorted someone, had their extortion scheme exposed, then posted an address that could be spend-linked to an address that ndnh posted to receive the proceeds from a loan. In that particular case, the evidence was intended to not stand up to scrutiny, as the address was posted in a giveaway/prediction thread whose deadline had expired, that ndnh was running(?). If someone had wanted the accusation to stick, they could have made minor adjustments to what they did.