The question is: why is it possible to place a 911 call without all that information being laid bare before the dispatcher and logged. There are extraordinary regulations on carriers for E911, and thus a means to impose that requirement.
It's an awful problem that will exist as long as people suck.
Right now, you could have extra caution for 911 calls which originate from VoIP. Pass a law that in five years telco CEOs are charged as assisting murder the next time a SWATing happens and they’d magically discover that egress filtering is easy to implement once you’re not looking at the revenue generated by spammers.
Second, you can argue anything will be a slippery slope (you should hear what people say raising the capital gains rate 1% will do) but it’s intellectually dishonest to pretend there’s no distinction between contributing to a violence death and “basically anything”. Operating critical safety infrastructure should carry responsibilities beyond the average business.