He can't fix something that wasn't made by him. They are using some L2Java files that have a strange RNG. That random isn't working per 1 skill used, or 1 mob spoiled like it should do. No, it is a random per X amount of seconds. You can test it at skills landing chance, drop chance, spoil chance, craft chance, enchant etc. If you will find what files they are using and take a look in there, you see that there is a random time for applying the rates.
Example: You. When you got that those EAA, for sure you didn't got them in a distributed manner of 100 monsters. The spoil of those 5 EAA was in a specific time and after that time went out, you didn't got anything. So, you can get 1 EAA per mob, 5 monsters one after other and suddenly you will get nothing for 95 monsters.
As I said, the random isn't applying for each monster, it applies in a specific time. This window of time can be found in those java files.