Incorrect number of likes displayed in posts

I noticed that only 1 like was displayed, but clicking on 'List' revealed 2 likes. Only after clicking on List 4 times did the display change to 2 as it should have been.

 

I've seen that happen. I think its purely down to timing. You load the page, there is 1 like. Then between you loading the page and clicking on the 'likes' link, someone else clicks like, so the list shows 2 people.