I am posting this at the risk of starting another war on airspeed vs. groundspeed...
There is one other thing to consider- what was the wind at the time? At the airspeeds you are at in slow speed flight, if the wind is more than 25% of your airspeed, you need to be concerned about the change in kinetic energy when you turn downwind.
The 25% is a rule of thumb I've found useful over the past years.