The fact remains that it's inconceivable why Robin Bain should have worn his son's new opera gloves, if he intended to suicide after killing them all! Why would RB search them out in David's room just to wipe the rifle when there was plenty of bedding, clothes, towels, etc. to hand, lying around the house? In my opinion, DB obviously didn't expect any fierce resistance from his younger brother and his gloves becoming heavily blood-soaked.
They were found under the bed...
http://www.stuff.co.nz/the-press/news/2296381/Bloodied-gloves-found-under-Stephens-bed
ETA: the glove I posted in the 2nd photo doesn't appear to be like those in the 1st, so deleted it. &%+((£
From the following doc page 133 and 134
https://justice.govt.nz/assets/Documents/Publications/2012-David-Bain-amended-report.pdf2.
Crown Reliance On David Bain’s Opera Gloves Found In Stephen’s Room
443.
Det. Sgt Weir also found two “opera” gloves in Stephen’s bedroom smeared with
Stephen’s blood. The Court of Appeal considered the bloodied gloves provided “support” for
the guilty verdict (para. 166). The Crown Law Office submits that the only rational explanation
for the presence of these gloves is that the killer wore them “to avoid leaving fingerprints”
and that Robin, having decided to commit suicide, had no need for such concealment. Of
course in the nature of these events, it cannot be said
when Robin decided to take his own life.
It may have been long premeditated. It may have been in the agony of a killing spree.
444.
David Bain has no explanation for how the gloves got to Stephen’s room but suggests
Stephen could “quite possibly” have borrowed them at an earlier date (“’cos he was well
- known for coming into, and borrowing stuff of mine just because he looked up to me as his big
brother. He liked getting dressed up in the things that I had.”)
However the appearance of the gloves in the photographs clearly suggests some involvement in the fight.
445.
The important point is that there is no evidence linking the gloves to David at any
relevant time except through ownership which, as the Crown properly argued in the case of
Margaret’s spectacles, is irrelevant. Robin’s hand is smaller than David’s. A smaller hand can fit
in a larger glove.