Try playing a video with Hebrew as the wiki interface language. The video controls are completely out of place and overlapping each other.
In general, there's no need to flip video controls for RTL environments. It's usually OK to keep LTR orientation for video players that are localized for RTL languages - the play button must point right, the progress slider must from left to right, etc. So the first step to fixing this would be to just force LTR orientation everywhere. The second step would be to make RTL adjustments in the few places that will need them - probably only the elements that have text (see Bug 27450, for example).