When two profiles are merged, the events (in the Timeline tab) should also be examined for duplicates to merge.
I just finished cleaning up a profile which had 9 'christening' events -- same name, same date. It also had several pairs and quadruples of some other events (same name, and either same date or no date).
In general, I would consider two events the same if they have the same name and date ... and thus could be merged (any other info in those original events would be "merged", but the people, name, and date would by consolidated into one event on that date with that name.