So if I, as a company, release something as open source (licensing the patents[1] with no royalty to anyone who's interested, as long as they follow the rules in the license), then I, as the same company, can turn around and sue anyone who uses it for infringing those same patents?

[1] I assume that when software covered by patents is released as open source, the patents are also implicitly granted as part of the license, because if they weren't no one would be able to use it for anything because they would be infringing on the patents.

The only situation this can possible make sense in is if Google has somehow violated the license, thereby revoking their permission to use the relevant patents and exposing them to litigation.