Weird warbler at El Valle

The Canopy Tower's Carlos Bethancourt forwarded a report from the Canopy Lodge's Faustino Sanchez and Danilo Rodriguez of a weird warbler they had a couple of days ago. Any guesses better than melanistic Canada Warbler?

Dr. Robert Ridgely had this to say:
By its overall conformation and the facial pattern, this is clearly a Canada Warbler. But my lord, what an aberrant plumage!
Dr. George Angehr added:
A check of references shows that Canada has hybridized with Mourning Warbler, which would perhaps give it that black throat. I also wonder if it might be a Canada/Hooded cross, since they are in the same genus, which could also produce a black throat. I can't find anything on what hybrids look like, though.