Yes, that's why I sometimes add a comment on someone's tree, though 'thanks I'll fix it' messages are somewhat rare in my experience.
Recently I found a cluster of about 20 trees all linking two siblings incorrectly to someone in my tree, despite a bucket load of readily available evidence to show who their father actually was. Two of the trees seemed to be owned by serious researchers, and I messaged one and added a comment to the tree of the other. The one I messaged did eventually reply but not very politely (understatement of the year!), while the comment I'd left received a grateful response within 24 hours, with their tree already updated.