You can only use a player who is not/no longer playing in the tournament. In RR that means no player is out, so it had to be someone who isn't playing.
The rule is there to stop someone playing on two teams, and causing a conflict of interest (what if losing with one team helps the other).
Bizarrely the NAH (old) rules allow it, and a team can object if they think the sub is too good (very subjective).
It's unfortunate, in your case in Bristol, as no-one was around to replace him, but thems the rules.
Because those are the rules.
You can only use a player who is not/no longer playing in the tournament. In RR that means no player is out, so it had to be someone who isn't playing.
The rule is there to stop someone playing on two teams, and causing a conflict of interest (what if losing with one team helps the other).
Bizarrely the NAH (old) rules allow it, and a team can object if they think the sub is too good (very subjective).
It's unfortunate, in your case in Bristol, as no-one was around to replace him, but thems the rules.