It's pretty much just an "educated guess". Visually, it does not appear to be a BCC.

If I remember correctly, someone has written up a faq on the web, describing several things to looks for to discern the two.

I believe, first and foremost is subcaudal, dorsal and ventral scale count. Then they count saddles, look at head shapes and coloration. It's a very tricky thing to get a 100% ID on an animal.