I used to hear a lot of the old time military high power shooters talk about guys who would ooch around during rapid fire, on purpose, and shoot extra rounds on other shooters' targets. These stories were mainly about interservice matches and usually involved trying to bring a particular shooter of grumpy disposition into a state of total apoplexy.
I had a Navy dental team shooting in the 1975 3rd Marine Division matches. In the practice sessions running up to that when I was trying to build my team one of my boys, DN Topaleski, was firing pretty wildly in offhand. Suddenly he started shooting 5's and pinwheel 5v's in offhand. His shooting became spectacular enough that several Marines started watching him. One Captain said to him, "By God, doc, we ought to recruit you for the Marine Corps!" At some point the line decided to have the pits investigate and it turned out the target pullers had gotten so disgusted they started marking the target like that to shall we say "muck" with old Tope. I think it was pretty discouraging for him to say the least because he quit right after that.
When I was up at Newport, RI, in 1974 taking my Navy dental officer indoc course I went to the indoor range they had up there and asked to shoot for qual. On the rapid and timed fire pistol stages I caught the Chief, out of the corner of my eye, holding the target button down and giving me a couple of extra seconds, I am pretty sure. I think I was kind of not at my best that day from club call the previous night. So there is "good" "mucking with" where they can help you out.
The one really raw deal I got was shooting Trainfire at Fort Sill in 1970 for my Army ROTC advanced camp and the near targets (like the "gimmie" 25 and 50 M ones from a dead rest foxhole position) were so shot up you could not get them to fall unless you could find a spot right on the edge. I had the second highest score in my platoon which was nice but it was only sharpshooter.