The simple answer here is common sense... The Athletic Commission in this area has always rounded weights since the Matt Serra v. Georges fight. In the video, it was an employee of the UFC talking to Nicks camp, making sure they were aware of the rules, not the AC letting Nicks camp know there was a change in the rules.
Every AC is allowed to adopt their own rules. They do not have to follow the unified rules at all. Its up to the UFC to decide if they want to hold an event where a commission sets rules that are too far removed from the unified rules.
All rules that have been quoted in this thread so far have been from the unified rules or the NSAC set of rules, which have NOTHING to do with this fight or any fight that has ever been held there.
There was no favoritism, the only similarity to favoritism is the rules are published in French, so GSP could certainly have a better grasp of the rules than a non-french speaker. But the same could be said about rules being published in English giving the non-English speaker a disadvantage here in the USA.
Dan The Ju