It’s not a huge technical blunder, that’s the point. I appreciate that what is seen cannot be unseen here and everywhere but this truly doesn’t matter at all and pretending that it does is strange.
It’s like insisting that the face scanner in Mando make any kind of technical sense. Would it make that scene better? Yeah, probably. But the important thing is that Mando took off his mask, that’s what matters. Would that scene in TLJ be better without that goof? Yeah, sure. Is that scene still exciting, visually interesting, and compelling for the characters? Yes, and that’s the thing that matters the most.