There is a high chance of scattered tracks hitting the EPD from the BBC. To check this in simulations, I investigated the secondary tracks having an creation vertex (origin) at at least 4.5 cm and maximally 85 cm from the beam (i.e. x=y=0 in lab coordinates). Here are the resulting plots, zoomed on the BBC and EPD range of z = +- 370-390 cm:

On both sides, there is scattering both the BBC and the EPD, as well as something after that, at around 385 cm, more pronounced on the negative side. Also, something created 1000 scattered tracks in these 600 events at ~ -377.8 cm.

If we look at their transverse momentum distribution, it is clear, that a large part of them have a very small momentum (pt<20 MeV), but that's not even 50%, a significant fraction has a considerable amount of momentum, around 100 MeV or above.