I recently came across this client crash issue: http://pastebin.com/FSt0G7cM
It happens if I hold a FunkyLocomotion wrench and have EnderIO covered conduits in my FOV.

The reason for this lays in the wrench class generator (https://github.com/rwtema/FunkyLocomotion/blob/master/src/main/java/com/rwtema/funkylocomotion/asm/WrenchFactory.java). When scanning the interfaces in ItemHelper.wrenchClassNames for methods, it does not look into superinterfaces of those classes, therefor missing the crazypants.enderio.api.tool.IHideFacades.shouldHideFacades method as crazypants.enderio.api.tool.ITool inherits that interface. To fix this, you'd have to take the superinterfaces into account.