They were once married, but contrary to a lot of lazy media coverage in the build up to the awards, remain friends and even consult each other on their respective film projects.
Cameron urged his ex-wife to do The Hurt Locker after reading the script and even screened Avatar for Bigelow several times in post production to solicit her opinion on the sci-fi blockbuster.
Also, both films were – in their different ways – about the Iraq War as Cameron pointed out in an interview with CBS recently.
Someone has also done a nice Muckety map of the connections between the two directors.
In a way, it all worked out nicely as Avatar scooped the technical awards it deserved, as well as becoming the biggest grossing film of all time.
Meanwhile The Hurt Locker went from a film that almost no major studio wanted to make or release to a Best Picture winner that also made Bigelow the first woman to get a Best Director Oscar.