Both the Stipps said they did.
I would suggest that they would also be the only ones able to have heard both sets, given their close location and the bathroom window having been opened most likely by RS either looking for a way out or even just to get some air, since OP claims he woke up because it was so hot and humid but then for some reason just had to close the patio doors(cutting off the sound carrying out that side of the house) and bring in the fans... just before the first set of "shots" were heard which I believe was OP trying to bash the toilet door open while RS screamed for her life...
This is a pretty good pic of the estate:
![opneighbours2.jpg opneighbours2.jpg](https://www.websleuths.com/forums/data/attachments/64/64533-4a672f8aebda5fc2afe84931f66ca27a.jpg)