Nic, I think you underestimate Apple's interest. They are a company with tenacious leadership. If buying Interdigital puts Google at a competitive disadvantage, Apple would do it in a heartbeat.
And guess what, if Apple buys Interdigital, it will put Google at a big disadvantage that may cost Google billions and billions of dollars (even if the government makes our dollar worthless).
Then they will owe billions and billions of Yuans.
Regardless, Google will owe a fortune if they don't get wireless patents for protection.
IMO