The "laser shotgun" design appears to be counterintuitive, as, unlike a ballistic weapon, there seems to be little point in splitting laser beams. However, this is hardly a new idea in science fiction - both Spacehounds of IPC by E.E. "Doc" Smith and The Puppet Masters by Robert Anson Heinlein feature "fan beam" mode for rayguns, which spreads several beams across a horizontal plane. It also appears that the energy required to messily tear a human target in two in a millisecond is comparable to the output of a conventional rifle.
The Scatter Laser appears to work on a pump action, like a regular shotgun. It's possible that what's ejected and replaced are either burnt out heatsinks or spent power cells.
This is the only laser weapon that does not have an EXALT equivalent.