I also considered how the second assailant left the crime scene.
Only three alternatives are possible.
a) The individual left somehow without being detected. This is a possibility, the assailant could have snuck out that night and avoided cameras, or they could have stayed the night, and left in the morning and blended in with the usual morning activity on the street. Remember, that there was no video of the NW entering or leaving the Sherman's property. So the possibility of someone entering the property from Forest Heights Blvd from the rear undetected, is possible.
b) The TPS may have seen someone and identified and interviewed that person. We on this forum do not know who the TPS has questioned. This is not unusual TPS procedure, as in the Bruce MacArthur case, they questioned Bruce, and released him without laying charges, while they continued watching him and collecting more evidence. The TPS has stated that the NW is a POI, they have not stated he is the only POI.
c) There was no other assailant other than the NW. If we assume the NW was only assailant, he must be a unique individual. The TPS does not know who he is, they cannot find him, and he killed two people without the use of a weapon (gun, club, knife, for example).
MOO