What was the point of Brad's gay sister? She contributed nothing to the plot and was simply shoe horned in for political correctness. I found the openness of her relationship with her girlfriend very implausible - in that era being gay was not generally accepted and approved of in ordinary people's lives. They would have kept it well hidden. Another implausibility was the command to murder his wife by his own hand - no investigation - no trial - no defence - no attempt to use her to feed false info to the Germans or debrief her on what she knew. It didn't make any logical sense.