I think you'll find you're far happier if you can avoid thinking like this. Putting any thought towards these kind of minor "misdeeds" or even keeping track of them is a draining way to live.
I think the point is more about time management for the person offering their help to anyone who reaches out. There is an incredible sense of helpfulness in the startup community and a pay it forward/back attitude. When new entrepreneurs, or old alike, reach out for help, your first instinct is to help them because you know how hard it is to be an entrepreneur. This is despite being super busy and drained yourself. So, when you make time for someone, even though you may not have much time to give, it's quite a waste when they take it for granted. It's not about holding a grudge, more about making a decision to help the people who respect your time and value it, and not wasting your time helping people who seem not to.
I don't think the author is "keeping track" of anything. If I say, "Hey, will you review my YC application?" and you say, "Sure, but get it to me before Wednesday or I won't have time." and I say, "Will do!" and then you never hear from me again, you won't be recommending me for anything. And likely, you won't take the time to help me if I try to reconnect, unless I have a pretty good reason I flaked.
It's not a list, it's human nature. You invest in things that show promise, and the behavior outlined above doesn't show promise.
