“Traditionally, fiduciary [liability] insurers have recognized a DOL investigation as a covered claim only after the DOL has sent a letter identifying alleged breaches of fiduciary duty at the end of its investigation. Under this structure, there is no coverage for defense costs during the investigation period. Pre-claim investigation coverage changes that. As soon as the first notice of an investigation is received from the DOL, filed with the insurer and accepted as a claim, the insurer is obligated to start paying defense costs.” (Segal Consulting)