The following happened in a teams-of-four match:
East opens 1, South doubles, West takes a pack of bidding cards out of the box (under Dutch regulations meaning that he has made a call), and says: "Hold it, I didn't see the double". TD lets him substitute this for a redouble (erroneously aplying L25A), and NS go for -1400, which, combined with the result at the other table, costs 16 imps.
At the end of the match (EW's team won, 22-8) the TD realises his error and applies L82C. He reasons that he has to consider both parties to be non-offending, so EW's team keep their 16 imps and win by 22-8, NS's team do not have to suffer the loss of 16 imps and lose by 11-19, so the final result of the match becomes 22-11.
No, sorry. Certainly Law 82C applies but that does not mean that EW necessarily keep their 16 imps. What he does is to assign scores based on him giving a correct ruling, treating each side as non-offending.
Let us consider what might have happened. The bidding goes 1 X ?/TD. The ruling is that no change is permitted under L25A. So the TD moves on to L25B and gives the following options:
The substituted call may be condoned .......
What substituted call?
The trouble is that L25B assumes the player has attempted a substitution. Ok, I suppose we have to ask him what call he is going to substitute. What do we do if he answers "I am not going to change it if I cannot change it under L25A."? Oh, dash it!
So, for assigning purposes, we look at these possibilities and see where they lead.
Ok, which of these are likely?  certainly is, but he might commit himself to L25B.  - not a chance!  is possible: now faced with a loss of 3 imps, West might cut his losses and go for this.  is also possible, now that West has got embroiled.
Given that we now apply L82C, and treat each side as non-offending. Which score is best? For EW +630, 11 imps in, for NS -150, 6 imps out. That's what you assign. Of course, I am guessing as to the results of contracts but this is the correct approach.
TDs must assign scores where the Law Book tells them to.