FACEBOOK NOTIFICATIONS?

[Duncan]

If I liked a comment someone else made on a photo my friend was tagged in, will the person who made the comment get a notification and my friend who was tagged in the photo get a notification too? I quickly undid the like as I did not me to like it in the first place.

[Matthew]

The person who made the comment is the only one who will know.
The only way that friend will know that you had an involvement with the picture is when that friend makes a comment, and you make a comment as well. Or if they make a comment and you like the comment.
And if it's the friend's picture, they will only know if you have liked or commented on the picture itself, not if you have liked someone's comment on that picture.