"This is an expanding trend in the circuits. When the record does not refute the claimant's alleged disability, and [the plan administrator is] on notice of a treater who may have information related to the claim, either: [1] obtain a release and secure the 'readily-available' records, or [2] alert the claimant of what specific records are missing." [Harrison v. Wells Fargo Bank, No. 13-2379 (4th Cir. Dec. 5, 2014)]