Question about cross platform code

Hello, I'm new to using Ignition and I have been reading these forums to address specific questions I've been having. I came across something I wasn't sure about in this post:

http://www.inductiveautomation.com/forum/viewtopic.php?f=70&t=9761&p=34091

Namely, I'm not sure about this line:

Can anyone explain why you have to use two different events to make your project be cross-platform? Also, what platforms are we talking about specifically? Linux, OS X and Windows? Is there a guideline somewhere out there that gives rules to follow regarding cross-compatibility?

Thanks.

There’s not too many places where you need to be concerned about this, but as it happens on Windows ‘mouseClicked’ events are generated on the button press, whereas on OS X they are generated on the release.

That post is somewhat inaccurate it would seem.