Despite the story being told backwards and dealing with problems we adapted to and solved we filmed chronologically with our murder scene being filmed first,then running and fire with the climactic suicide of our husband character.
Before we filmed we wrote out what we needed done, what time was required and when best to do it. Due to our tight schedule we pushed to film the majority of our narrative in the one night. Filming commenced around 8pm but soon we encountered a prop problem of finding a suitable liquid to serve as blood. Ultimately we went with red food colouring as our 'blood' and it worked out well enough.
In regards to the falling over shot we decided to change the shot from something like this:
1:12-1:16
to more of a slower collapse where our character drops to their knees then drops in front of our husband character.