Nobody was shot or assaulted, nobody broke down any doors, or did anything ‘massively disproportionate’ here.
In this case nobody was shot or assaulted. In other cases people have been.
That the man in question did nothing deserving of a legitimate SWAT response means that for one to have happened was massively disproportionate. Because a SWAT team is a disproportionate response to doing absolutely nothing to provoke one.
1. Someone calls 911 reporting an armed conflict reporting an active shooter situation.
2. Police respond, sending a SWAT team.
3a. Tense situation was resolved, unfortunately resulting in a heart attack.
3b. Suppose there was an actual gunman. The fast response would have saved lives.
You're sitting at home knowing post event debating the situation knowing the actual events that are taking place. The police only know 1 version of the events, which they hope are in good faith. In order to argue that the police's response was disproportionate, you would have have to known beforehand the report was bogus. But this is impossible, so the police must bring enough force to deal with a legitimate call.
The trade off here is due diligence versus response time. In the fast majority of cases, people don't abuse 911, so the polices' fast reactions are beneficial. You have to leave it up to society to minimize these types of edge cases.
Also, making a fake phonecall to the police and describing a graphic situation to the police is not so trivial and easy. Pouring some gasoline on your neighbors house and burning it down or emailing bomb threats are also trivial tasks that children understand are wrong.
Swatting being so easy is ridiculous but that doesnt absolve the kid of any guilt.