I don't beleive that BPs need a seasonal temp drop to breed. I don't cool mine (I heat the room) and I had no problems. I know there is a difference in temps between where I am in FL and where you are, but my snakes are in a climate controlled room, so the cooler temps outside have nothing to do with it. I also know other breeders who do not drop temps for breeding. It seems more likely that the high side temps on top of being in the warmer garage were too much. My room is heated to 84-85F year round, BUT there is no direct heat in my racks so my snakes really never get over that 85 degree temp. I've had great results this way, over a period of about 4 years, so I personally think maybe BPs don't really need high temps in the 90F range. I agree with you that something caused your slug problem, I just doubt it was the lack of a seasonal drop.

Disclaimer: I realize that ambient heat/no direct heat is not an option for everyone, and I don't advocate that everyone take the heat out of their racks. I am happy to discuss my setup in more detail, just not trying to hijack this thread.