This is an annoying issue for developers, the game actually recompiling script from the unpacked file even if -filePatching parameter is not set.
Just set up an unpacked file at your root folder of DayZ, like if you want to use -filePatching.
Put something in the script that will not compile it.
Launch your game without -filePatching parameter set.
The game will still tell you that he can't compile script, even if he should not compile an unpacked file.
It sounds like only happening if the number of files inside the unpacked file is not equal to the number of files inside the mod.