Here's one way I know of for sure creates this scenario. You know how when you're skipping bases and all of a sudden get a cnfo and then you end up getting stuck in a rival base as if it were yours? Well, if you don't hit "done" and go ahead and drop troops, you can actually attack the base, and here's the catch, the droidekas won't move and there are no active traps anywhere. So you can proceed to roll the base with ease, and if you play it out till the end, the game will award you the results YOU SEE. Of course, the defender, upon seeing his replay of the battle, will see it with his dekas and traps active, so the result with be very different. Most likely the attacker will lose in the replay and show a score just like you mentioned, but that's not what was actually registered by the game. What was registered was what the attacker saw during his attack.
It's not really cheating, per se, but it is a scummy thing to do, and is a major bug that should have been patched ages ago.
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LINE ID: syncpan77-FULL-RESTRICTED NO OP WAR SQUADTop 15 squad on GSOW in UCL