So, I'm somewhat burnt out on trying to fix bugs and make mods. The lack of any feedback from SD, GPG, or the community combined with my own schedule have really unmotivated me. My own personal whining aside, I have some ideas about this.

Watching the video I saw a couple of things.

1. The game lasted around 20:34 according to the end game clock, the in game timer said it was only 14 minutes long.
2. The Rook shoulder mounted ToL was having frequent target lock issues. It was locked onto the Oak for most of the game. It frequently was not firing.
3. The trebuchet also displayed the target lock behavior.

My idea about what is going wrong has to do with LOS. More specifically, I believe it may be the case that target locking occurs if the current target is lost from view (via either moving out of visual range or teleporting) while within weapon range. Without going into the LUA more, this does sound possible. Consider the following. Distance is calculated by the difference between the current position of a unit and its target. If a target's location is not known (i.e., LOS is lost), then what happens when distance is calculated? Calculating the distance between a known location and an unknown location is not possible, hence when this process occurs the result is an error (or at least unexpected answer). This of course is conjecture, and may not be the case.

How to test this:

I tried testing versus the AI, however the AI is not very cooperative about retreating or teleporting. Testing with real people seems to be necessary.

Tests:

1. If my hypothesis is correct, then target locking should not be possible with Full LOS (i.e., no fog of war).
2. A second more complicated test is as follows:
   
   1. Take the +5 vision radius misc gadget item. 
   2. Play starting at level 10 and hoardes of gold, so the Rook can immediately acquire shoulder weapons and buy lots of health and armor items.
   3. Buy lots of Health and Armor items for both test demigods.
   4. Move the Rook to the center of a creep wave. They will be the test objects to see if the shoulder weapons are targetting correctly.
   5. Destroy any towers or other objects that would grant additional LOS.
   6. Move the enemy demigod within range of the trebuchet (its range is normally farther than visual LOS). The trebuchet is useful for this test because you can see it swivel to match its target's current location.
      
   7. Move the enemy demigod around to see when or if targetting locks.
   8. Move the enemy demigod back into visual range and have the Rook drop the goggles. This should place the enemy demigod outside of LOS.
   9. Move the enemy demigod around to see when or if targetting locks.
3. Mod the goggles to have negative LOS (-10 I think should do it). This may demonstrate the effect more readily.

If someone would want to find some people to test it, I would be interested in the results.

Did it bug when teleporting to another location in LOS or only when going outside of LOS?

I went ahead and did some testing.

• With full LOS versus the AI I wasn't able to replicate the Shoulder Weapon target locking.
• I modified the Totem of Revelation to have -20 Visual Radius. I was able to achieve target locks, however if further review I can't get it to lock consistently.
• Buildings are odd when it comes to visibility. The Rook was always able to target them with his weapons even when they were out of modified LOS. Units were not able to be auto-targetted in the Fog of War.
• The Trebuchet has a minimum range of 10. If the current target moves within this range, the trebuchet will never fire at it, nor select another target.

Some other things of interest.

In the melee demigods and siege archer blueprints there is an interesting variable in their weapon description. This variable is AlwaysRecheckTarget. For the melee demigods this is set to FALSE. For the ranged siege archers it is set to TRUE. It is absent from the other units. This may fix the shoulder lock if added to the shoulder weapons.

Update:

Okay this is driving me nuts. I still have no idea what circumstances lead up to the target locking. I've watched the recording that Spooky provided and I still am not seeing why it happens. It is also a bit annoying to have to spend 12 minutes fastforwarding the recording everytime.