Program: 22450
Project: 22450
Buggy source:
@SideOnly(Side.CLIENT) @SubscribeEvent public void onDrawScreen(RenderGameOverlayEvent.Post event){
  if (event.type == ElementType.ALL) {
    Minecraft mc=Minecraft.getMinecraft();
    EntityPlayer player=mc.thePlayer;
    Item equipped=player.getCurrentEquippedItem() != null ? player.getCurrentEquippedItem().getItem() : null;
    MovingObjectPosition pos=mc.objectMouseOver;
    if (pos != null && mc.thePlayer.getCurrentEquippedItem() != null && mc.thePlayer.getCurrentEquippedItem().getItem() instanceof IPipeWrench && ((IPipeWrench)equipped).canWrench(player,pos.blockX,pos.blockY,pos.blockZ)) {
      TileEntity te=mc.theWorld.getTileEntity(pos.blockX,pos.blockY,pos.blockZ);
      if (te instanceof IWrenchDisplay) {
        ((IWrenchDisplay)te).displayWrench(event);
      }
    }
    if (CrossMod.BOTANIA) {
      if (pos != null && player.getEquipmentInSlot(4) != null && player.getEquipmentInSlot(4).getItem() instanceof ItemExosuitArmor && (player.getHeldItem() == null || player.getHeldItem().getItem() != BotaniaIntegration.twigWand())) {
        ItemExosuitArmor chest=(ItemExosuitArmor)player.getEquipmentInSlot(3).getItem();
        if (chest.hasUpgrade(player.getEquipmentInSlot(3),BotaniaIntegration.floralLaurel)) {
          Block block=mc.theWorld.getBlock(pos.blockX,pos.blockY,pos.blockZ);
          BotaniaIntegration.displayThings(pos,event);
        }
      }
    }
    if (pos != null && mc.thePlayer.getCurrentEquippedItem() != null && mc.thePlayer.getCurrentEquippedItem().getItem() == SteamcraftItems.book) {
      Block block=mc.theWorld.getBlock(pos.blockX,pos.blockY,pos.blockZ);
      ItemStack stack=block.getPickBlock(pos,player.worldObj,pos.blockX,pos.blockY,pos.blockZ,player);
      if (stack != null) {
        for (        ItemStack stack2 : SteamcraftRegistry.bookRecipes.keySet()) {
          if (stack2.getItem() == stack.getItem() && stack2.getItemDamage() == stack.getItemDamage()) {
            GL11.glPushMatrix();
            int x=event.resolution.getScaledWidth() / 2 - 8;
            int y=event.resolution.getScaledHeight() / 2 - 8;
            int color=0x6600FF00;
            RenderItem.getInstance().renderItemIntoGUI(mc.fontRenderer,mc.renderEngine,new ItemStack(SteamcraftItems.book),x,y);
            GL11.glDisable(GL11.GL_LIGHTING);
            mc.fontRenderer.drawStringWithShadow("String_Node_Str",x + 15,y + 13,0xC6C6C6);
            GL11.glPopMatrix();
            GL11.glEnable(GL11.GL_BLEND);
          }
        }
      }
    }
  }
}

Fixed version (ground truth):
@SideOnly(Side.CLIENT) @SubscribeEvent public void onDrawScreen(RenderGameOverlayEvent.Post event){
  if (event.type == ElementType.ALL) {
    Minecraft mc=Minecraft.getMinecraft();
    EntityPlayer player=mc.thePlayer;
    Item equipped=player.getCurrentEquippedItem() != null ? player.getCurrentEquippedItem().getItem() : null;
    MovingObjectPosition pos=mc.objectMouseOver;
    if (pos != null && mc.thePlayer.getCurrentEquippedItem() != null && mc.thePlayer.getCurrentEquippedItem().getItem() instanceof IPipeWrench && ((IPipeWrench)equipped).canWrench(player,pos.blockX,pos.blockY,pos.blockZ)) {
      TileEntity te=mc.theWorld.getTileEntity(pos.blockX,pos.blockY,pos.blockZ);
      if (te instanceof IWrenchDisplay) {
        ((IWrenchDisplay)te).displayWrench(event);
      }
    }
    if (CrossMod.BOTANIA) {
      if (pos != null && player.getEquipmentInSlot(4) != null && player.getEquipmentInSlot(4).getItem() instanceof ItemExosuitArmor && (player.getHeldItem() == null || player.getHeldItem().getItem() != BotaniaIntegration.twigWand())) {
        ItemExosuitArmor chest=(ItemExosuitArmor)player.getEquipmentInSlot(3).getItem();
        if (chest.hasUpgrade(player.getEquipmentInSlot(3),BotaniaIntegration.floralLaurel)) {
          Block block=mc.theWorld.getBlock(pos.blockX,pos.blockY,pos.blockZ);
          BotaniaIntegration.displayThings(pos,event);
        }
      }
    }
    if (pos != null && mc.thePlayer.getCurrentEquippedItem() != null && mc.thePlayer.getCurrentEquippedItem().getItem() == SteamcraftItems.book) {
      Block block=mc.theWorld.getBlock(pos.blockX,pos.blockY,pos.blockZ);
      ItemStack stack=block.getPickBlock(pos,player.worldObj,pos.blockX,pos.blockY,pos.blockZ);
      if (stack != null) {
        for (        ItemStack stack2 : SteamcraftRegistry.bookRecipes.keySet()) {
          if (stack2.getItem() == stack.getItem() && stack2.getItemDamage() == stack.getItemDamage()) {
            GL11.glPushMatrix();
            int x=event.resolution.getScaledWidth() / 2 - 8;
            int y=event.resolution.getScaledHeight() / 2 - 8;
            int color=0x6600FF00;
            RenderItem.getInstance().renderItemIntoGUI(mc.fontRenderer,mc.renderEngine,new ItemStack(SteamcraftItems.book),x,y);
            GL11.glDisable(GL11.GL_LIGHTING);
            mc.fontRenderer.drawStringWithShadow("String_Node_Str",x + 15,y + 13,0xC6C6C6);
            GL11.glPopMatrix();
            GL11.glEnable(GL11.GL_BLEND);
          }
        }
      }
    }
  }
}