I've never been on an adcom and I couldn't tell you what adcom members are likely to do, unfortunately. I doubt that your anecdote would make anyone disregard your application, especially if the prompt specifically asked for that information; I just think that what you wrote doesn't provide enough relevant information to make adcoms excited about accepting you. That would be in the rest of your SOP. So, the impact:length ratio of these paragraphs is pretty low. Again, I don't think they are hurting you, either, except for maybe placing too much emphasis on your past instead of on your future.
I've had discussions with professors about abstract-writing and abstract-reviewing, which I imagine is a similar situation to SOP-reading, and what I've been told is to imagine that the reviewer is tired, hungry, doing his reading at the last minute and will not spend more than precious minutes skimming each submission. You want to help them by being clear and concise, and you want to lead with the important details. In an SOP that means - what you want to study in general (subfield) and what interests you in particular (specific questions/areas), and then how your background prepared you to study those questions and why you want to go to school X (fit: who you want to work with, what resources appeal to you, etc); plus other information, as is requested and as is relevant. Additions that don't contribute to your "argument" (why you should be admitted) are simply not helping your cause.
