[[1.8.9] PlayerInteractEvent - Client/Server - Right-clicking a ladder]

I have a question about the PlayerInteractEvent, specifically the different behavior on the Client and Server threads when the player is right-clicking on a previously-placed ladder block while holding another ladder.

 

Given the following test code snippet:

@SubscribeEvent
public void clickOnLadder(PlayerInteractEvent event) 
{		
   if (event.pos != null) {			
System.out.println(event.pos.getX() + " " + event.pos.getY() + " " +event.pos.getZ());	
System.out.println(event.world.getBlockState(event.pos).getBlock().getLocalizedName());
   }	
}

 

When right-clicking a placed ladder with an empty hand, I get:

[22:58:56] [Client thread/INFO] [sTDOUT]:  -324 82 412

[22:58:56] [Client thread/INFO] [sTDOUT]:  Ladder

[22:58:56] [server thread/INFO] [sTDOUT]: -324 82 412

[22:58:56] [server thread/INFO] [sTDOUT]: Ladder

 

When holding a ladder, I get:

[22:58:56] [Client thread/INFO] [sTDOUT]:  -324 82 412

[22:58:56] [Client thread/INFO] [sTDOUT]:  Ladder

[22:58:56] [server thread/INFO] [sTDOUT]: 0 0 0

[22:58:56] [server thread/INFO] [sTDOUT]: Stone

 

Is the client-side event somehow suppressing / not sending to the server as a result of holding a ladder?  When holding a ladder, on the Server-side, this makes it impossible to get the coordinates of the clicked block.  Could someone please explain why this would be?

 

Thanks!

 

Using Minecraft 1.8.9 with Forge 11.15.1.1902.