Well, as far as I know there have been people known to break the "cheat"/file modification protection. But those are usually quite simple .xml modifications affecting only variants. Code changes to game logic (lua) would be possible working around the protection I guess, but actual code changes on the C++ code (reticule, hit detection etc.) without having access to it are pretty much impossible (unless you want to go into reverse-engineer-hell and thereby illegal areas) and were already quite painful due to limited access to the engine. Also don't forget, there is a reason, why that code is not freely available. Development of this mod started with specific terms and those are in no way enforceable by making the code free - the contracting parties would lose any control over the enforcement of the terms.
Our friend Vlaad put it perfectly right already: The business model of MWLL was flawed, we knew it from the very beginning that this IP includes complications. Now I consider it kind of sad because I'm still sure we would have delivered over time what the community really wanted. On the other hand, this community proved also to be extremely complicated, sometimes unforgiving, sometimes unthankful and we devs also did plenty of stuff wrong in acting with and managing it. And then of course there is the "life continues" aspect. Some of the devs study and are currently (including me) in the process of finishing those studies. It is kind of interesting. Actually I was only part of the development for merely 8 months, but still I love thinking back to that time and would even love to pick it up again. I just regret very much that I could not get my planned work done, which would have made this game much more presentable in ways that just become more important in current time (streaming, lets-plays, league spectator presentation etc.) and were just slowly developing when I planned those features. I can only imagine how it is for the devs who actually spent years on this project and who even had far more ambitious plans.