The curator of the University of Michigan Museum of Zoology had this to say upon receiving the warbler specimen yesterday:
"It was 6.9 g, and the pectoral muscle looked thin. It didn't look like
anything was wrong with it. No tumors or parasites I could see, no mites
on the feathers. I'll save the stomach, and I saved tissue and a partial
skeleton and pickled the syrinx. I think I'll pin it out with one wing
spread. It will be a nice skin."
This is very interesting as some theorize that vagrants show a higher incidence of brain tumors or other problems. In this case, the bird may be nothing more than a natural extreme genetic variant in the population.
It also appears that my scale was not very accurate!