The vast majority of white tail disease is in fact Staph. aureus bacterial infection and wrongly ascribed to the spiders as far as I understand. Also wrongly ascribed to an allergic reaction. Not infrequently there is delayed presentation and appropriate treatment as the victim and some times their health advisor thinks it is a spider reaction.
Of course no idea as to what went on with your poor friend but it would not be the first time even in the antibiotic era that someone had an amputation for staph disease.

