Apartheid-era South African flag in Invictus

I was watching Invictus a little while ago on DVD. During the final match, I noticed the old, Apartheid-era South African flag being waved. I actually backed up the disk and paused it just to be absolutely sure, but, really, there aren’t any other flags that one could be mistaken for at the resolution I saw it.

Now the weird part: This is in no way a spoiler, because it was not a plot point. There it was, big as all outdoors, waving right alongside the new post-Apartheid South African flags and the bonny blue New Zealand flags, and absolutely nobody mentioned it.

So, I suppose my question is twofold: Was this a mistake by Eastwood, and could that flag have been used in that context at that time?

No mistake, and definitely yes, it was used, and mostly as deliberate provocation.

Although it’s not used that way by everyone

Thanks for the reply, but now it seems very odd that it wasn’t a plot point during the match.

I think it was downplayed to provide a more inspirational, “rainbow nation” story. IIRC, it was mentioned in the source book, Playing The Enemy