The Nazis may never have found the headpiece if they hadn't followed Indy. That's his primary contribution. He clearly knew exactly where Marion was, even thoug

The Nazis may never have found the headpiece if they hadn't followed Indy. That's his primary contribution. He clearly knew exactly where Marion was, even though he bullshitted the spooks about it. So he was careful with that information, and it's not likely anyone else would know. Here's a question: how do we know those were government spooks at all? Maybe they were Nazis trying to setup Indy just so that they could follow him :D