The most certain way to succeed is always to try just one more time.

You cast the false memory charm once more and with the addition of the confundus charm, you wait for a reaction from the man. And you get it; the shudder which characterizes the confundus charm means you've successfully hit your target.

The man stands for a few seconds, looking down at the stick in his hand and then up at you again. He carefully places the stick down on the ground, wipes some of the dirt off his suit and gives you a nod. "WELL, I'd love to stay and chat but I have a meeting to go to. Toodles!" He turns around and starts to walk away from you. Only to stop and look around himself in confusion. "Excuse me," He clears his throat and faces a stem of a tree. "I fell and hit my head and now I can't find my way to the elevator. Could you point me in the right direction?"

You've successfully confused the man and all memory of the attack or your patronuses seem long gone. Do you leave the man to chat with the trees? Or do you try to take him with you?

All these choices...