Must be a Canadian thing. The shelter here doesn't groom the dogs, to be honest I'm happy to no longer walk the kennels and see dogs who'd been sitting there for days with gaping skull wounds full of flies (the previous shelter before this one).
We have groomers that volunteer their time at the local shelters and rescues (my friend is a local groomer that does so as much as she can).
As far as it's story goes, I'm not sure, but there is a mandatory 3-7 day hold down here depending on the shelter, so the owners have/had their chance.
I usually takes quite a few trims to shape the hair to be in a continental trim. So I'd guess that the dog was trimmed that way beforehand. I've seen dogs in shelters that have had a groomer tidy up the animals, but I've never heard of a volunteering groomer choose a Continental trim.