I think the more important question was how they came up with the number. If you lack the ability to go through your apartment in your mind and count the windows AND do not happen to remember the number outright, it might indicate something like aphantasia.
Absolutely -- but realize at that point you're asking a brain for an explanation of how it operates. Self-reported data in social science is not the most robust.
Especially in the situation where you're trying to figure out if someone has constructed their own methods to mimic 'normal' ones. The more effective and internalized the method, the less likely the person is going to be able to identify and report it.
Just look at all the people who are saying they're surprised to learn that "picture it in your mind" is meant to be literal. Their mimicry is so effective they can't recognize it in themselves.
