The kids came up with the rules, not the teachers, which seems like a pretty important distinction here.
Then they continued to have to figure out what to say to get the Lego back.
No, they were made to write new rules together this time. Nothing in the article stood out to me as coercive. The teachers made the kids actually think about what they were doing and discuss openly, instead of each kid blindly indulging their own self-interest.
the exercise would continue until the answers were acceptable