Ah, then I believe you're stuck. I don't know of anything in the base game UI that tells you when/if clemency is back up. Best bet is to /feedback it in game as its a good idea to have this in the base game.
Attempt to use -->> Success? Yay! Profit!
-->> Fail? Run! Run like heck for a door/exit/Outlaws' Refuge (Bonus points for having Footpad...) or dive in deep water where guards can't follow. RP going "Neener, neener."
Regardless, Khajiit proclaims that this one is innocent of all crimes.