Not sure about video footage, I don't recall thinking anything was unusual during the match other than that David's opponent playing a various complex line in an opening new to him which was way too complicated for me to understand (not saying much I know). I spent most of the Olympiad shushing noisy arbiters and stopping photos being taken during the games to notice suspicious behaviour from opposing captains thoughMichael Jones wrote:
As to the evidence of guilt, the texts between Marzolo and Hauchard seems to demonstrate fairly convincingly that the moves at least got as far as him - unless either of them can come up with a reasonable alternative explanation for sending numerous messages consisting of apparently random numbers whilst a chess match was in progress in which the recipient was a team captain, which neither of them has tried to. Hauchard's system for passing them on to Feller seems trickier to prove, though - was there any video footage from the Olympiad which might show Hauchard standing behind the relevant players immediately before Feller made the corresponding move?
I'm trying to visualise where the match was played. If it was played in the first row of matches then there was seating alongside board 1 for each captain and the match arbiter/official. If, as I think was the case, it was played in the second row then there was no seating for captains and so I'm less likely to have noticed anything unusual as I would have spent less time in close proximity as the seating was further back.