The Cons courted and set up this deal but lost government before they could implement it.  It was the Liberals' Dion who issued the permits that actually enabled it. At that point the Trudeau government had made its choice, the same choice the Cons would have made had Harper been returned to office. 

All the fine words about human rights is just the usual Liberal spin, but had they actually denied the Saudis these weapons the Cons would have decried the Liberals as job killers. Such is partisan politics. Ontario jobs trump Saudi lives. 

The loss $15b and 3000 jobs would cost an awful lot of votes.