Father Oswald Tesimond claimed that Keyes had "tasted persecution himself, having lost his goods because of it" while historian and author Cyril Northcote Parkinson's image of him was of a "desperate man, ruined and indebted". Tall, with a red beard, despite his relative poverty Catesby declared him "a trusty honest man", and may have paid him for his services.
According to Father Oswald Tesimond, Keyes had personally faced persecution, resulting in the loss of his assets. Historian Cyril Northcote Parkinson portrayed him as a desperate individual, financially ruined and indebted. Catesby, however, saw him as a reliable and honest person, possibly even paying him for his work.