I actually messed up my testing. It actually works fine. :)

The 1.7.10 version of this mod is no longer being maintained. However, it seems like it is an issue solely between Thermos/Spigot and SpecialSource that just happens to be triggered by a Realistic Torches during preinit. I'm not sure there's anything I could do about this anyway, except disable moving light sources completely (the error occurs when the tile entity is being registered).