Re. FRC GENERAL COMPETITION REGULATIONS
Stewards and Penalties No.2 of 7 - Regs...
2. If a car drives through or bounces a car ahead in the same lane causing it to de-slot . . . This penalty may be assigned by a steward or the victim may call a "drive-through", identifying the offending car...
What's the point in calling DTs and you cant identify the offending car.
In cases like this (maybe cars are going way too fast) when one doesnt know who drove through them - it should be considered a racing incident

Luke