While Hemenway is totally justified in being steamed by Robertson's taking judicial notice of blogging and twittering in affirming a presumption of Obama's eligibility, Robertson's dismissal effectively defeated discovery of Obama's eligibility and trial on the merits until after the inauguration including any determination that Obama is not de jure POTUS.
Hollister's claims that he is entitled via interpleader to challenge the authority of the CIC is "innovative" and I haven't seen any persons claiming to be lawyers who think it had a chance of succeeding even it it reached trial.
Thus until a quo warranto hearing decides otherwise, Obama is both de facto and de jure POTUS. Hemenway can't expect the court to act as though Obama was only de facto POTUS based on allegations never admitted into evidence at a trial.
As to the anonymous lawyers to whom you have spoken: Is there a basis for their opinions or are they just guesses based on such factors as "unthinkablity" rather than legal precedent?