Recently the forge version 14.23.5.2768 has become recommended and this mod is causing crash in the game after initialization.
Says LexMano in this session (3th comment)
http://www.minecraftforge.net/forum/topic/66711-forge-1122-142342768-startup-crash/

java.lang.VerifyError: Operand stack overflow
Exception Details:
  Location:
    net/minecraft/client/renderer/chunk/RenderChunk.func_178581_b(FFFLnet/minecraft/client/renderer/chunk/ChunkCompileTaskGenerator;)V @542: aload
  Reason:
    Exceeded max stack size.

PassableLeaves does not transform the class net.minecraft.client.renderer.chunk.RenderChunk or any other class that has any interaction with it.
My guess, from a cursory examination, is that the changes made by Mine Camera are causing your issue. It may be clash between it's class transformer and another coremod's transformer (OptiFine?).
In any sense, it's not PassableLeaves.

Ok thanks =)
And sorry, I do not know to see a log, Lexmanos gave me a list with the mods that said in the LOG in "warning", so I decided to report.