Hi, I work on the ISS Meteoroid/Orbital Debris Team. In this case we actually can tell the difference.

Firstly, I must state that we don't know it was an impact that caused the leak. Anyone saying otherwise is jumping the gun. Won't know until we get better imagery and even then might not know definitely.

A major reason we know it's not orbital debris (man made) is that the leak location is on the wake-side of the vehicle (opposite the "ram direction"). The vast majority of orbital debris threats to the ISS come from a cone about 30 degrees off either side of the velocity vector. Impacts from behind don't really happen as it would likely be co-orbital with the ISS and not approaching at a substantial relative velocity.

I can also say it likely wasn't one of the Geminid meteoroids (the leak occurred during the Geminid Meteor Shower) as the leak was on the starboard side of the Soyuz and the Geminid radiant vector was on the port side for the entire duration of the meteor shower.

But again, still not sure it was impact-induced. If it was though, likely a random background flux meteoroid.