copyright notices or other copyright rights management may be a separate violation of copyright law.
Although Getty has adopted a "sharing" approach to use of its photos online, it's unlikely that the stock photo company will tolerate unlicensed uses in a documentary. Should the company learn of your use; they may send you one of their infamous settlement demand letters. (The company also offers guidance for recipients.) If you're using photos that are similar to Getty pictures but not owned by Getty, then you'll need permission from whoever owns the copyright to that imagery, as well.
Fair use questions? Perhaps the information we've posted here can help. And please see the informative comment provided below.