I'm not sure if sending S.W.A.T.-like team to "investigate" is sensible.
The U.S. managed to investigate things by sending detectives for a long time. Other countries seem to manage the policing without the need for equivalent of S.W.A.T.
S.W.A.T. teams are equivalent of Special Forces in Army. They are armed with extremely dangerous weapons and highly trained to kill. You're only supposed to send those people when there's a reasonable suspicions of armed resistance, not on routine investigation of white-collar crime, just because you can.
I've seen quite a bit of debate over whether the media is mischaracterizing what happened with the whole "SWAT-like teams" bit. Local law enforcement has said they didn't deploy any SWAT units, and, so far as I've been able to find, while the DoE OIG does own some shotguns[1], they don't have any real tactical teams.
Given the way the rest of this has been reported, it's kind of my suspicion that a bunch of investigators in "POLICE" raid jackets and a few shotguns got turned into a "SWAT team" by reporters.
Are there other details which still haven't been revealed? Was the dude a well-known organized crime figure? Was his home bristling with weapons? Had they already tried the sensible "knock on the door" method? I don't know. But I've been bitten enough times by important details left out of the story to make it more sensational that I'm disinclined to get too outraged over things I've read on the internet until I've heard both sides of the story.
The U.S. managed to investigate things by sending detectives for a long time. Other countries seem to manage the policing without the need for equivalent of S.W.A.T.
S.W.A.T. teams are equivalent of Special Forces in Army. They are armed with extremely dangerous weapons and highly trained to kill. You're only supposed to send those people when there's a reasonable suspicions of armed resistance, not on routine investigation of white-collar crime, just because you can.