This was actually a pretty common practice in the Yugoslav partisans. It was actually seen as a morale booster by the higher brass, that promoted the aggressive spirit of the fighters, inasmuch as everybody got to keep any equipment they personally captured (with the exception of the venerated MG-34/42s which were always in high demand by the heavy MG-lacking partisans, and probably 'officer' equipment, like maps, binos etc).
Also, the capture of the aforementioned MGs was so highly valued that the individual responsible might well receive a medal for the deed, and conversely a court-marshal or some other punishment for abandoning one in the field.