sexing Rosy Boas

Prior to going to the NARBC at Tinley Park, IL, I probed my three young rosies to verify their sex. All three probed to be male. At Tinley, BHB had some Rosies I was interested in and asked if they could sex them for me because I was wanting females. The guy started looking for spurs and when I asked him to probe them, he said that that was not an accurate predictor in Rosies as all of his males and females probed to the same depth. Now this caused some concern because now I am thinking maybe my males are not males. I went home, checked my books, checked Rosyboa.com, and other sources and they all made reference to probing.

My question is, is probing in rosy boas accurate or is the presence of spurs the more accurate predictor. Any input would be beneficial.

Thanks,

Probing is usually accurate.
If you want to be sure, popping is a method that is usually accurate. Though, whatever you pop a female, make sure you pop it a few more times, because they could've been holding back their hemipenes. I dont see the problem in probing though, a lot of people say that is the most accurate way.