Tripwire hook duplication with door and armor stand

The tripwire hook are dumplicate when continuously placing the tripwire hooks in the water

 

Step to Reproduce: 

1. Placing a door
2. Destroying one block next to the door
3. Placing the water near the hole( water should be perpendicular to the door)
4. Leave 2 blocks from the hole and place one solid block witch is perpendicular to the direction of water
5. Place a tripwire hook and a string
6. Place a armor stand above the string
7. place a target and then connect to the target block from a block with tripwire hook with 4 blocks above the armor stand
8. Place 5 redstone above the solid block and a target
9. Place tripwire hooks under the water constantly

Observed Behaviour:

The tripwire hook are duplicating when continuously placing the tripwire hooks in the water and getting more tripwire hook

Expected Behaviour:

The tripwire hook no longer duplicates when placing it in the water