No, that is absolutely not another issue. If we don't hold people responsible for misusing these resources, there simply is no remedy here. SWAT teams cannot be expected to be fully prepared for both a hostage situation and a so-called prank.
Pranks are generally fucked up shit anyway. Pranks that can turn deadly so easily should not be called pranks. They should be labeled serious crimes and prosecuted accordingly.
Furthermore, I get rather tired of blow hard Europeans imagining they know what is best for internal matters of the US and that policies that work in their country would obviously work exactly the same here. If your country works better than the US, good for you. That isn't evidence that you know what is best for the US.