Up the local park this afternoon i saw a woman i thought i was on friendly terms with,so as she looked at me from about 30 yards away i raised mt left arm at the elbow with my palm facing towards her,fingers slightly bent as to not appear too formal. I was shocked to see that i'd made a mistake as on looking closer i realised she wasn't a friend but a foe! The dog she had with her was the same type as the woman i'm on friendly terms with has. Anyway,the damage was done,i'd politely acknowledged a person i'd rather ignore/avoid. On realising my mistake i kind of raised my other/right arm at the elbow and pretended i was doing some sort of elbow exercise in the hope she'd stop thinking i'd made a friendly gesture to her. My question is when you wave/shout at someone in a friendly fashion,then wish you hadn't done because it isn't/wasn't the person you thought it was,how do you save face?