I'm with you there. I still don't think we've got the full picture yet. If the drop is just caused by this news then it shows that sentiment about MPG is pretty bad anyway.
And I'm not sure what effect an NZX complaint about MPG is going to have when it's news about a competitor rather than MPG themselves. MPG somehow aren't following the listing rules by not releasing possible news about a competitor's future actions? That seems like a bit of a stretch.