I haven’t had the same experience but similar as in going to the wrong address. I’ve had a couple of guests who have knocked on a neighbour’s doors instead of mine despite the fact that they had my full address. The neighbour in question is disabled, he had to come down his stairs using a walking stick to get to his front door in order to answer their door. It must have been an inconvenient especially as it has happened more than once and has nothing to do with him. I apologised on both occasions and was luck the neighbour was very understanding. I suppose the fact that your guest arrived in the middle of the night made it worse.
On both occasions I questioned the guests and they admitted they had written the number of the property but not the letter after the number. I usually e-mail guest's a day to two prior to arrival confirming checking in details etc. and now, I specifically inform then that they must take note of the exact door number because my disabled neighbour has been inconvenienced as a result of guests knocking on their door instead of mine. So far, this has done the trick for me and some guests even call or message me when they are outside to say they are outside the building.
Perhaps restrict late check-in and if you are to agree any as exceptions, then inform the guest that they must ensure they do not knock on any other doors other than yours. Maybe even arrange a sign between the both of you so they can easily identify your property i.e., a red traffic cone, or a some object that you can place outside your property somewhere easily visible. Then send them a picture, this way they will know not to approach any property unless this object is in plain sight. I'm sure guests would be accommodating of additional measures you may request given the early hours of the morning.
I don’t know what implications this could have in LA if the neighbour complained but hopefully you will manage to soothe them over before it escalates to such levels, sort this out between yourselves and a gift basket as you suggested might be a nice way to approach them. Equally important are any additional measures you can put in place going forward to reduce possibility of similar occurrence.
BW, Ama