Air traffic controller 'left work early', one was left to handle the air traffic

The ATC is faultless in the incident: listen to the audio, he confirmed multiple times the handoff to visual separation. At the last second, he even asked if they had visual as he saw the potential collision and alarms were going off. Fairly certain the fault like 100% with the helicopter pilots.

I wouldn't be so eager to jump to this conclusion.

After listening to a former pilot on this type of aircraft, who flew this very aircraft into this very airport, the many problems are clear:

- This particular helicopter was flying too high when it should've been around treetop/obstacle-avoidance level where it was

- Helicopters shouldn't be flying through an approach path of a major airport

- TCAS won't do a damn thing <1000' AGL. Perhaps subsequent versions of TCAS should address traffic around airports and down to around 200' AGL

- DCA should scale back on its traffic volume

- The approach change from 01 to 33 is awkward

- The FAA needs to exhaust all avenues to encourage, hire, and train ATC to bolster its ranks rather than send emails about how to quit or allow commercial figures to pressure its leadership to resign

Also, I really want to know if:

- The AA jet got a TCAS TA (advisory) because they definitely didn't receive an RA (warning)

- The ATC controller was in ADS-B filter mode or was seeing all data

We'll never know if:

- The chopper pilot mistook another aircraft for the AA one or was giving the answer expected due to being on NVGs in busy airspace