Plane collides with Blackhawk helicopter Washington DC

[putnam6]

The issue is that the radar may have been displaying 200 feet, when they were actually higher. The radar in the tower is fairly low fidelity, so it may have read a lower altitude than the Blackhawk was actually at, which would have added another layer to "They're going to miss" mentality by the controller. They won't be able to verify until tomorrow when they can read the CSMU from the Blackhawk.

Im just trying to wrap my head around it all, and put the map with the video, another thing isn't ATC supposed to call out heading and altitude? as in "flight xxx maintain adjust whatever the proper course heading and altitude, etc. and aren't you referring to the ATC radar? 

What did the altimeter in the helicopter say?