Alain,
Many details here:
http://surfcity.kund.dalnet.se/falco_bob.htm
On 29/10/1940 one BR.20 made a forced landing at Stene on its way with other bombers to Ramsgate, England. This may be your BR.20.
No mentioning of human loss.
BR.20 MM21904 appears to have participated in a raid on 11-11-1940 so wasn't a write-off on 29-10-1940.
Groet,
Leendert