Well, I'd say more like an Inquisitor should already be on site at the outpost because things that happen because of the Warp are usually things people would notice. Once he confirms presence of Warp-based phenomenae he'd probably send a holo back to command, wherein they'd dispatch a proper Inquisition team to investigate and quell the problems. 

Meanwhile it'd be left to the Imperial Guardsmen on the outpost staff to handle the problem until the proper Marines arrive. I don't think a commissar would be a sight you'd see on a mining outpost on a wintery fringe world. Yes, if it were a military outpost, but a mining colony would have, like, a barebones security team a la The Thing.