Scammers will say anything to scare people.
http://800notes.com/forum/ta-de071afa5bd5041/dangerous-new-trend-in-irs-scams
Dangerous New Trend in IRS Scams
Also, if someone makes "a false report resulting in the police or SWAT showing up" THEY would be the ones in trouble for falsifying a police report. They would be in WAY more trouble than the person they reported on who simply (supposedly) owes a debt.
No. It's called swatting they call in a fake situation at your residence and claim there's a gun man. It has been happening and Chicago PD stated this has happened several times as well as in Kane country and DeKalb. This particular group has been known to do this if you do not cooperate. It's all false reports but it temps you into paying them.
By the way, which "particular group has been known to do this"? I don't see an actual name for this caller here. Because if they're "known to do this" I would expect the police have already dealt with them making false reports.