I am pretty sure RI's can be caused due to being too cold. So it sounds like you did cool them maybe a bit too much. I would double check your setup.
As far as slugs are concerned, I really think cooling them too much can cause an increase in slugs. Two years ago I had one clutch 8 slugs. Last year I had 6 slugs total out of 42 eggs. This year zero slugs out of 44 eggs. The only thing I changed was reducing the cooling period to about 4-6 weeks then bringing temps to a more consistent level with no night time drops.