Although you could have blushing, even at 35% humidity if the dew point was high enough, I think Ty's experience is what probably happened to you, as I also had a similar experience.
On one plane many years ago, I noticed that the white looked somewhat yellow, or "dull", after spraying clear. I used a gray primer. If, at that time, I tried to get the clear on in less than ideal atmospheric conditions, I most likely used too much retarder.
Retarder is a slower drying thinner. If too much is used, it can work its way down into the dope layers, softening them and then you have problems. Another factor is how heavy the clear coats were that you applied. If you had a high retarder content, then too heavy an application could cause problems.
The total amount of retarder should be as little as necessary to prevent blushing. The Randolph dope guide says that the total retarder content should not be more than 20% of the total thinner content.
Let's say you are going to mix a total of 8 ounces of clear dope/thinner mix and you want a 50/50 final mix. If you go by the Randolph guide, you will mix four ounces of unthinned clear with 3.2 ounces of thinner and 0.8 ounce of retarder.
If atmospheric conditions are good enough, you should not need any retarder at all. If you do use any then use as little as possible.