For more background info I think this is the same incident being discussed here
http://www.pprune.org/forums/showthread.php?t=255777
and here
http://www.pprune.org/forums/showthread.php?t=255670
suggested responding to MayDay's be avoided
I thought that in the air (and at sea) it is contravention of the law to knowingly disregard a distress call.