Well we know it's a red card for a handball that stops the ball going in the net (see Willian vs utd, or Suarez for Uraguay vs Ghana). In our case the ball hadn't got that far, the ball only had the keeper to beat - I don't see how that's less bad that when a striker is pulled down to stop them having a shot against a keeper.I always thought the double jeopardy rule applied predominantly to goalkeepers bringing attackers down when they’re through on goal (and inside the box)? Rather than it being a penalty, red card and a forced substitution, it’s now just a penalty (and often a yellow depending on how intentional the “bringing down” was).
I have zero idea how it applies to defenders handling the ball for a clear goalscoring opportunity, if it even does?