But, it's not aikido. Maybe just an open hand to hit them off balance.
Jim, be careful when you define what is and isn't Aikido. There may be a time when it's perfectly good Aikido to lay someone out, block or whatever else, including significant injury or worse. As others here have pointed out before, loving protection includes not only the attacker but yourself and others.
At the dojo I'm currently at, a student was killed a number of years ago and it involved a struggle as I understand it (before my time). My instructor made the point that if she had gouged her attackers eye's out, done any number of heinous things to him and lived we'd have been thrilled because she would still be alive and practicing. I've never been with an instructor who hypothesized otherwise, nor, would I likely stay with one.
I'm not saying it's perfect philosophical Aikido, nor what I want to practice regularly, but I sure wouldn't call it bad Aikido if it saved someone's life. You use what you've got from where you are and make the best of it.