You can't flip any of those shots without creating more continuity errors. You flip the shot of him walking up stairs and Han & co are coming from the wrong direction from the previous shot and Hans gun belt is also on the wrong side. Flip the shot of lobot coming down the stairs and the stormtroopers are reversed (and you can't just flip Lobot either). It's only a problem since the SE's, thanks to the window as the original "windows" could well have had the corridor go all the way around the back. But, Lobot could always have doubled back when the attention was not focused on the rear wall, so i see no need to do anything here.