That depends on whether any further documentation has come to light. I doubt any has come to light. It doesn't matter regarding whether it wasn't in Bamber's statement. Where is the sound moderator in relatives' statements concurrent with its discovery? If something comes to light that shows force arms were drawn after there was movement noticed in the house, then that blows out of the water any trick of the light claims.
I doubt any has come to light too! And I doubt any ever will!
I think it rather does matter. If it is had the sort of importance to it that Bamber/supporters are trying to attach today then why didn't he mention it in his witness statement, interviews, trial?
How would anything blow the 'trick of the light' out of the water? No one can be sure what it was and the system will simply write it off as a 'trick of the light' falling back on the silencer and Julie Mugford plus all the other evidence for good measure.