I'll say!

huh thats strange

I was wrong. If SSL Ridley sticks to a wall of a stage, regardless of placement, and gets hit, Ridley rises to the top of the screen, and loses a stock. After losing a stock, he doesn't respawn.

I found out a glitch where in a stock match if SSL Ridley sticks to the upper wall of a stage and loses a stock while still having a few stock left, Ridley doesn't respawn back to the stage.