Another small update - I spoke with the wife today. Apparently she speaks much more English than her husband does, so we were able to have a good conversation. It seems that our grill was the "final straw" in that she is very, very frustrated with the apartment in general at the moment. Her number one frustration is the restaurant downstairs, which recently added a vent from their kitchen into our mini-courtyard which is both noisy and smelly for 20 hours of the day.
I had not noticed as we never open the windows that open into the courtyard (as I mentioned in the first post, we could see directly into our neighbor's bathroom and bedroom if we did, and there really isn't fresh air as the courtyard is SO small - so we open the windows that face the main street instead). And my husband is always the one who grills, so I honestly never set foot on the balcony. But today I stepped onto the balcony when she mentioned this and wow. The noise is unbearable and the smell is that sort of greasy fast-food oily smell (if that makes sense).
So, when we grilled last week, it was the icing on the cake of unhappy smells for this couple.
This further cements my idea that for the time being, we'll use my indoor grill pan when we want to "grill".