I speculate that a junior REALTOR® in the Toronto luxury home market is under strict orders that, if they encounter something unexpected, they are not to do anything without getting instructions from the boss. Especially if it involves, in any way, shape or form, the police.
After all, the owners being found murdered in their pool room while the home is actually for sale, could have a significantly negative impact on the sale and therefore the commission. Even more importantly, the murders might actually have been associated with the actions of a REALTOR®, such as being careless with keys or showing the house to the wrong type of people. And yet more importantly, the other clients of the REALTOR® could be so disturbed by the association between the REALTOR® and the murder of the homeowners, they might actually change realtors. And an even further massively scary implication could be, that the murder of this couple in their luxury home, while it was for sale, could be just that little unexpected pin prick that bursts the inflated Toronto luxury real estate market, leaving nothing but a ragged bit of balloon.
So, I speculate, this is why, after 30 or so minutes of discussion, the housekeeper was told to phone 911, rather than the REALTOR® who actually found the bodies.