He did it out a sense of duty. It does happen, you know.
And what possible reason could Edward have to want more than one witness? The more witnesses, the more the story could have leaked out.
If Stillington stepped forward after Edward’s death out of sense of duty, why didn’t he do it at the time Edward married Elizabeth Woodville? Where was his sense of duty then? Talbot was already married to Butler by that time. Why didn’t he come forward then either? I guess after almost 20 years, and Edward’s death, he finally had a flash of conscience, and spilled the beans about a previous marriage he officiated at, that had no witnesses, and under church law, was not a valid marriage either. Kind of sounds like all the “me toos” claiming sexual harassment many years after the fact. No proof, but it sounds good, and gives them their 15 minutes of fame.