The serifs certainly are a dead giveaway, however, there is different amounts of spacing between the top of the bar and the bottom of the character. Additional

The serifs certainly are a dead giveaway, however, there is different amounts of spacing between the top of the bar and the bottom of the character. Additionally, the gray one is visibility off center even in the small image - I'm sure the other ones too. If they just did an 'add error bars' to Excel and had them be any value, it wouldn't have been discovered (well, that wouldn't have been the issue - the other issues with lack of data and such still would have been present).