OK the fact that hes 8 and had a tantrum is completely unacceptable.. Sounds like the parents need "parenting School' to help guide him..
As for your lesson. wasn't harsh enough..
Time out - alone in a room-without an audience
a 'job' to pay for the cost of the replaced item
and grounding would of been just a few actions I would of done, but better believe there would of been more consequences when we got home!!!