Odd top margin when using one_half shortcode

I am presenting an odd issue with a top margin when using the shortcodes for one_half. Please see the link I am adding bellow.

If you scroll down to the tabbed content, you will see that the first tab there is no margin between the text and the two columns layout. If you click on the second or third tab, you will see there is a huge top margin on both. These margins are being added through a class named: column-top-margin

However, the code I am using on all 3 tabs is exactly the same. The spacing between text is also the exact same, so I am not sure why the second and the third tab is adding that top margin class.

I appreciate any inputs.

Thanks!