By investing, they co-own the company (at least partly), right? Seems smarter than trying to license the tech in 10 years.
You can't just use tech from some other company even if you are part-owner. Heck I don't think you can even do that from a fully-owned subsidiary. They have to have structural/legal independence or it's really just a different branch of the same company.
That's one of the principal points that tax auditors check in a group, although it's oftentimes hard to determine a market price.