Sounds strange to me....
The TCAS does not warn of heavy traffic. Period.
For the software in our Airline, it will only guarantee a display of traffic out to 7 miles, although it MAY display targets out to 40 NM.
When traffic gets close, you get a aural warning and the target goes from white to yellow.
When the TCAS senses a trajectory of both aircraft colliding, it issues a Resolution Advisory to each of the aircraft. The target goes from yellow to red, and aural commands are given such as Descend, Descend, and a red rectangle appears on the ADI indicating the pitch required for the traffic resolution.
In our flite manual it says that any pitch changes should be slow, and not be felt by the passengers.
Sounds to me like someone tried to make the Resolution Advisory into a strafing run.