When in a slide layout which has a textbox with the ability to insert table, chart, image or movie (like 'Title, Content'), if you move your mouse over the video reel icon, the toolip says 'Insert Movie', but if you click it the dialog that appears says 'Insert Audio/Video' (master) or 'Insert Movie and Sound' (4.3 and below). I think the tooltip and dialog should be changed to 'Insert Audio or Video'.
I believe the icon should also be changed as well, but i guess that would need another bug report. :)
With LO 126.96.36.199 (Win 8.1) the tooltip for this icon shows "Movie and Sound" and if I click on it the title of the dialogue box to insert the file shows "Insert Movie and Sound".
Regarding the mentioned discrepancy:
Therefore, it is probably no discrepancy in LO 4.3 or do you mean another thing?
Note to the Steps to Reproduce:
To see this icon you need to activate the INSERT toolbar by VIEW -> TOOLBARS -> INSERT
Thanks for spotting this!