If he knocked the pole down it's pretty likely it didn't get put back up in the same place. It was never .5 metres up either, stupid rule that tbf though, Si was quoting BC not UCI. Thing is I don't think he didn't ride out of the tape because it was badly taped, he rode out because he was a bit out of control, so that could only be a technicality I suppose
Last time I bothered to read the rules, you had to rejoin where you left, which I think meant "between the same poles". But I hear there were changes for this year?