No you're spinning it by saying "It was a pranking attempt that fell flat". Either way do you really think it's okay for a CEO to "prank" users by silently editing their posts then only admitting to it after being caught. Seems like the "prank" excuse is a spin.

If it was a prank he would have done it and admitted it without getting caught in-between.

Also, it has to be funny to be a prank, otherwise it's bullying, where was the punchline?