Would be interested to learn if the motivation for recovery was based on location or for investigative purposes.
The article mentioned that the mishap casual factor was mechanical and that the salvage was to determine more specifically what had gone wrong.
Also, it's free to the end user to request salvage for a mishap. If memory serves the cost of salvage comes from the safety centers budget.
A sister squadron lost one of our 60R dipping sonars in several thousand feet of water. Brand X didn't want to "go through the trouble" of requesting salvage but our CO told them to request salvage and go find the damned thing. NSC did all the legwork in getting the salvage ship, divers, etc. I even got invited on the planned two week long recovery op (no thanks). As it turns out it took the salvage guys several hours to get to the bottom of the ocean and then they found the sonar in 15 minutes. Sonar was recovered, returned to the OEM, refurbed, and reissued. Not only did the salvage recover a limited quantity asset it also reduced the cost of the mishap from several mil to several hundred K.
All that said it also doesn't seem like good business to leave a hornet in irans backyard. Not that they don't already have access to an RQ-170.