The use of sleeping pills has since come to the fore after league players were revealed to be mixing energy drinks and pills in the week before the Rugby League World Cup final last year.
Rugby Players' Association head Rob Nichol, who helped to deal with the Rugby World Cup incident involving Jane and Dagg, said it was not unusual for players to use sleeping pills when they needed to get rest after a late-night game.
"Where the poor decision was made was to have more than one and to decide to sort of experiment a little bit and play around," he said.
"Rather than just chilling out and relaxing and going to sleep, it tipped over the edge and they ended up going out to a bar.
"Now lucky for everyone, and including the boys that were involved at that time, no one was hurt.
Jane apologised for his "stupid choice that night". After the match at Eden Park, he said "I knew I had to put in a good performance after making a poor decision the other night and having it thrown all over the paper ... I knew I had to go out there and play well."