After reading this thread I have this to add for the original question...
Aikido techniques in and of themselves are not new or unique to Aikido. The human body only moves in certain ways. Joint locks only work certain ways, no matter what the martial art. So at the physical level, aikido techniques are not different to any others.
I have to agree with anyone else on this thread that said techniques become 'Aikido' when the intent to use them is based on aikido philosophy.
Aikido rule #1: "There are no rules"
I.e. Reply 1: if you survive, it is Aikido
The others I cannot argue on simple rules, but you'll understand
reply 2: If the opponent survives it is great Aikido
reply 3: If you can sit afterwards together and have some softdrink, beer, wine, sake, talk about what has happened, and why nobody has been hurt, well then go out and find O'sensei. You have to teach him.
One negative reply:
If you attack someone or hurt or kill him willingly, it is NOT Aikido, whatever technique you applied.
IMO this nails it.