Down here, brown and black bears are the "same" animal while grizzly bears are larger with a hump over their shoulder. The grizzly is known as Ursus arctos horribilis while the brown is just Ursus arctos, the grizzly being a sub-species of the brown-bear and the Kodiak is just another name for the grizzly (which is region dependant).
There are also hybrids of grizzly with polar-bear with the last known being shot during a hunting trip in 2006 - there was quite a stink about that one.
Semantics aside - there seems to be a bit of a personality difference (at least here in southern Alberta) between our grizzly and black/brown populations .... either way, hope the teens heal quickly and get back to the outdoors again ...