I don't think any video footage was shown when CB apparently confessed to DR in a Lagos bar in 2017
"
He became a suspect in the Maddie McCann case in 2017, when he confessed to D.R. (full name in article), a Portuguese friend, on the 10th anniversary of Maddie's disappearance, that he knew everything that had happened. R. immediately informed the police, but there was a lack of evidence to arrest him. The British metropolitan police were informed and an investigation began with the German and Portuguese police, who had initially investigated and ruled out Bruckner among 600 'persons of interest'"
Article no longer exists at the link, but I believe it was also reported in UK press
El estremecedor relato del pedófilo alemán acusado del secuestro de Maddie
*DR was in Lagos on the 7th May 17, he could have been in Germany 2 days earlier on the 10th anniversary, but imo the "confession" took place in Lagos
ETA
It seems according to this article that CB did indeed show a video to DR in 2017
"It was when the German was in a bar with his Portuguese friend Diego Rivera and they saw a note on television about the tenth anniversary of Maddie's disappearance. Brückner told Rivera that he knew everything that had happened in the McCann case. And then he showed the video of the rape of the American retiree."
Una conversación con un amigo en el bar y el video de la violación de una mujer de 72 años fueron las claves que dirigieron el foco de la investigación contra el alemán Christian Brückner.
www.clarin.com