I always thought this was a double homicide from the beginning, but I was familiar with Apotex.
I also know this street very well from the late 1980's when I used to house sit a home on it. At that time, it would not strike anyone as a "millionaire's row" type of place unlike the Bridle Path area, don't know if that has changed. Certainly if you know real estate values in that area one could expect they would be wealthy. There are large old trees that obscure the houses from view, and the house I know looked like a modest two story from the street but was actually a massive home, on a huge ravine lot that went really far back.
JMO I don't think TPS had any idea of the extent of the Sherman's wealth for the first day or two. Or the litigious nature of Barry Sherman and Apotex. There are many rich people in Toronto but not like Barry and Honey. Their names were also not splashed around much like other philanthropist Torontonians. Toronto Jewish community would know them, but by virtue of Apotex making generic drugs, it was not a household name. The officers first on the scene might not have realized the whole situation.
So the easiest conclusion, the path of least resistance, for TPS was m/s when they found a somewhat elderly couple dead. Then IMO, on day two or three, someone in TPS figured out these are actual billionaires, and the case needed much more investigation, and everything changed IMO.
TPS can't say something like "we didn't know who they were when we first found the bodies and now we are looking at this more carefully".