Look as with all rules its because enough people took advantage and a law has been created. Its about preventing abuse where one guy will catch his limit of fish run in "gift" his fish and go out and catch more. Your allowed to keep 1 days limit of fish you can give it away but you can't retain more than 1 limit of fish.
http://www.outdoorcanada.ca/record-5...-investigation
If you can party fish this guy would be a Hero since you can't party fish this guy is a zero.
Must have been a reason he was watching you because really so would I.