There's always that ONE GUY who has to throw out the "you forgot ---" in a poll thread. You sir, are "that guy".
2 of the 3 vets I took my ball pythons to said that my snake was either too young to properly sex, or too dangerous to attempt to probe or sex at their size... Excuses really. The vet I ended up sticking with double-checked the sex of my snake via probe, even after I told her that I bought the snake as a female. I thought that was pretty cool.