Looks like a BCI to me.
Did the pet store really say they "hatched" them, because boas give live birth. It just would show they are lying or don't know what they are talking about.

If you want to you can count scales but it is hard to do without a complete shed.
http://www.redtailboas.com/morphs/morphs.html

"Boa constrictor Imperator (BCI) have 253 ventral scales (or less) and a midbody scale count of 55-79. 21 or more dorsal blotches (saddles)"

"Boa constrictor constrictor's (BCC) have 234 to 250 ventral scales and a midbody scale count of 89-95. Less than 20 dorsal blotches."