In their quarters, Troi expressed concern that her Worf would not return when they closed the quantum fissure. When they made contact with the right Enterprise, they had a Worf on the bridge that dispels that hypothesis.
In one of the alternate timelines, Data states that Worf and Troi have been married for two years, one month, and twelve days. He also says that the romantic relationship -- not the marriage -- began shortly after Worf recovered from his spinal injury, but that would have been less than two years prior.
In the final scene, Troi gives Worf a birthday gift. As they talk, the bow on the top switches sides.
When Deanna takes the painting from Worf, she turns it the other way up, but when she hangs it, it is the same way up as when Worf held it.
When Worf records his personal log in the shuttle on the way back to the Enterprise, he says that "several contestants were maimed" in the bat'leth competition. When he replays the log for Dr. Crusher, he says in the log that "several contenders were maimed."
When Worf checks his personal log after the Cardassian attack on the Enterprise, he accesses "Any personal logs referencing the bat'leth tournament." The log mentions that he will not be able to attend and that his brother must take his place. But it still has the same stardate given in the other universes after the competition has ended.
However, given all the other changes to histories and personnel, it is perfectly possible that the dates of various events could have shifted between the different realities.
Around 25:00, Data's eye color is blue instead of the usual yellow. The eye color has been changed to help signify an alternate quantum reality.
After Captain Riker orders Data to backtrack Commander Worf's shuttlecraft route, Data leaves the Ready Room and heads left, a course which would take him into the viewscreen, rather than heading right towards one of the bridge's duty stations. This was a common production error on the show: when not in use, the viewscreen was removed from the set, and actors would enter and exit the bridge and ready room sets via this large opening. Actors who'd filmed a scene in the ready room would leave the set via the viewscreen opening when they'd completed their part and it was often caught on camera.
When the "Borg fighter" Enterprise explodes, there is no debris.
In one of the quantum realities that Worf comes to, he and Deanna Troi are married and have two children: Shannara and Eric-Christopher. But the quarters they are in (presumably theirs together) shows no sign that it houses a family of four.
When Worf orders champagne from the replicator, he does not specify the quantity, temperature, or any other details that the replicator usually requires, yet the replicator can be heard materializing his order.