That's pretty much exactly it.
It's a bouncy Spartan laser. Gief plx. :)
One of my finest moments in Halo 3 was getting a triple kill with a single Spartan Laser blast in Team Doubles. I don't know what combination of laggy bullshit and total lack of luck that involved, but I recall watching the video from the double victim's perspective; they went down immediately in melee range, then spawned in the tail end of the laser and died again.
I saved it, but it's no longer compatible with current versions. :(
...that is actually tied with the time I watched a guy jump down a tube onto my level with the SPNK-r in tow, and gravity-hammer batted the rocket back into his face. That felt goddamn glorious.