This same scenario can happen with too frequent of injections in the same area. Crashing gear or not.
The question is if you have a steril abcess or an infectious abcess.
If it’s a steril abcess then it’s from the gear not dissolving in injection and or too frequent of injections which is basically the same scenario.
If the abcess was infection based, meaning bacterial then either the infection came from the gear or injection habits.
One main cause of infection in the localized area is
1. People do not let the alcohol dry while swabbing the top and putting needle through.
2. Not letting alcohol dry on the body before injection. Contrary to belief pushing a needle through wet alcohol on body will not be steril. The area must be dry.
But the attention should be on the lab here. Especially if others have this tne product and others get infections it would be easy to blame the compound such as you did, versus bacterial laden products.