MCH Attack animations cancelled under certain conditions

Time: Always
Frequency: Always (if conditions are met)
World name: Ultros
Character name: Rado Banado
NPC name: n/a
Monster name: Any
Class/Level: MCH, level 52+
Party or solo: Either
In-game time: Any
Area and coordinates: Any
Steps:
1. Activate Gauss Barrel
2. Attack enemy with Split Shot, wait for cast bar to finish
3. Immediately as cast bar finishes, activate Reload/Quick Reload/Head Graze or any other off-GCD skill

Expected result: Split shot animation will play until the shot is fired, then the off-GCD animation will play.

Result: Split shot animation is completely cancelled and the off-GCD animation will play.

You can check expected result by doing the following:
1. Activate Gauss Barrel.
2. Activate Rapid Fire.
3. Attack target with Split Shot.
4. Immediately use an off-GCD like Head Graze.

Result: Split Shot animation will play up until the shot is fired, then the off-GCD animation will play.

Note: Black Mages and Summoners also finish their cast attack animation before playing into an off-GCD animation.

Completely seeing the animation disappear may lead to confusion regarding the status of the attack, and may give party members the wrong idea that you're cancelling your attacks altogether. This is important when movement is involved at the last moment before your cast finishes, which should result in the attack continuing... but wrong timing may cause it not to. This makes it unclear.