Program: 165718
Project: 165718
Buggy source:
@Override public void renderTileEntityAt(ElevatorTileEntity te,double x,double y,double z,float partialTicks,int destroyStage){
  if (te.isMoving()) {
    AxisAlignedBB aabb=te.getAABBAboveElevator(0);
    boolean on=MinecraftTools.getPlayer(Minecraft.getMinecraft()).getEntityBoundingBox().intersectsWith(aabb);
    double diff=on ? (te.getPos().getY() - (y + te.getMovingY()) - 1) : 0;
    GlStateManager.pushMatrix();
    RenderHelper.disableStandardItemLighting();
    this.bindTexture(TextureMap.LOCATION_BLOCKS_TEXTURE);
    if (Minecraft.isAmbientOcclusionEnabled()) {
      GlStateManager.shadeModel(GL11.GL_SMOOTH);
    }
 else {
      GlStateManager.shadeModel(GL11.GL_FLAT);
    }
    IBlockState movingState=te.getMovingState();
    GlStateManager.translate(0,te.getMovingY() - te.getPos().getY() + diff,0);
    Tessellator tessellator=Tessellator.getInstance();
    BlockRendererDispatcher dispatcher=Minecraft.getMinecraft().getBlockRendererDispatcher();
    for (    BlockRenderLayer layer : LAYERS) {
      if (movingState.getBlock().canRenderInLayer(movingState,layer)) {
        ForgeHooksClient.setRenderLayer(layer);
        for (        BlockPos pos : te.getPositions()) {
          tessellator.getBuffer().begin(GL11.GL_QUADS,DefaultVertexFormats.BLOCK);
          int dx=te.getPos().getX() - pos.getX();
          int dy=te.getPos().getY() - pos.getY();
          int dz=te.getPos().getZ() - pos.getZ();
          tessellator.getBuffer().setTranslation(x - pos.getX() - dx,y - pos.getY() - dy,z - pos.getZ() - dz);
          renderBlock(dispatcher,movingState,pos,te.getWorld(),tessellator.getBuffer());
          tessellator.draw();
        }
      }
    }
    tessellator.getBuffer().setTranslation(0,0,0);
    RenderHelper.enableStandardItemLighting();
    GlStateManager.popMatrix();
  }
}

Fixed version (ground truth):
@Override public void renderTileEntityAt(ElevatorTileEntity te,double x,double y,double z,float partialTicks,int destroyStage){
  if (te.isMoving()) {
    AxisAlignedBB aabb=te.getAABBAboveElevator(0);
    boolean on=MinecraftTools.getPlayer(Minecraft.getMinecraft()).getEntityBoundingBox().intersectsWith(aabb);
    double diff=on ? (te.getPos().getY() - (y + te.getMovingY()) - 1) : 0;
    GlStateManager.pushMatrix();
    RenderHelper.disableStandardItemLighting();
    this.bindTexture(TextureMap.LOCATION_BLOCKS_TEXTURE);
    if (Minecraft.isAmbientOcclusionEnabled()) {
      GlStateManager.shadeModel(GL11.GL_SMOOTH);
    }
 else {
      GlStateManager.shadeModel(GL11.GL_FLAT);
    }
    IBlockState movingState=te.getMovingState();
    GlStateManager.translate(0,te.getMovingY() - te.getPos().getY() + diff,0);
    Tessellator tessellator=Tessellator.getInstance();
    BlockRendererDispatcher dispatcher=Minecraft.getMinecraft().getBlockRendererDispatcher();
    BlockRenderLayer origLayer=MinecraftForgeClient.getRenderLayer();
    for (    BlockRenderLayer layer : LAYERS) {
      if (movingState.getBlock().canRenderInLayer(movingState,layer)) {
        ForgeHooksClient.setRenderLayer(layer);
        for (        BlockPos pos : te.getPositions()) {
          tessellator.getBuffer().begin(GL11.GL_QUADS,DefaultVertexFormats.BLOCK);
          int dx=te.getPos().getX() - pos.getX();
          int dy=te.getPos().getY() - pos.getY();
          int dz=te.getPos().getZ() - pos.getZ();
          tessellator.getBuffer().setTranslation(x - pos.getX() - dx,y - pos.getY() - dy,z - pos.getZ() - dz);
          renderBlock(dispatcher,movingState,pos,te.getWorld(),tessellator.getBuffer());
          tessellator.draw();
        }
      }
    }
    ForgeHooksClient.setRenderLayer(origLayer);
    tessellator.getBuffer().setTranslation(0,0,0);
    RenderHelper.enableStandardItemLighting();
    GlStateManager.popMatrix();
  }
}