Can't really tell by looking, it will depend on its pedigree or how well you can find out its lineage. There is enough variance in the "markers" for both BCC and BCI that it is pretty much impossible to tell them apart by visual markers alone. If you are not able to find out then it can be referred to as BCU for "boa constrictor unknown". Most important is that your friend has a healthy and happy boa. Great looking snake!