I agree that they were bounty hunters trying to hurry things along.
An investigation of the scope they were describing consumes massive amounts of resources; and knowing the payday, they may have leveraged some or a lot of those resources and the debt service has to be met.
They sounded very professional, but also sounded like hired guns or forensic accounting speculators as theorized by others. I concur and add that I think they are trying to improve the time-value-of-money equation to the extent they can. Time is money and no one more than those in a debt jam want it go quickly.