Well, I am a bit amazed at this one, as I cannot find any record of any Prophet being deliberately led into error by God. Most importantly, The seer known as "Thornbush", real name Marie-Danielle, is alive and well, as of this publication date, 21 September 1997. So even though William Kamm didn't actually make this particular prophecy, it is his signature that is used to propagate this message.
Thornbush, also known as Marie-Danielle, was, in the past "united"
with William. However, she, and her Spiritual advisor, Father Blais
of Quebec, had a "falling out", and Father Blais published a public declaration
in 1996, against William. The Public Declaration has some very strong things
to say about Williams activities. Since that time, William has been
"against" "Thornbush", and those "united with William" have also
been against her. Pretty obvious isn't it?