Bug at Openings Training?

first i have to say thanks for the site :)
if u have fo find for example 4 good moves at "Learn-Openings" and u do during the first 3 moves a mistake, u can avoid to loose points, seems.
u have to press on a exercise what u have already done (out of the history below) and finish the old one again. after it u can choose "Continue Training" and might get the same exercise where u done the mistake at first, without loosing points.

You can also just refresh the original exercise and make achieving the same thing even easier. I'm not sure you can call it a bug though when the explanation is, "who the hell cares". If you're cheating anybody by doing this, it's only yourself.

yeah, that why i do a questionmark ;)
wasn´t sure about if its a real bug