Mike Boettcher

It's not what I expected. It's a nice moment, but looking at the rest of the photo, Steve breaks with his old mentor. He doesn't see what Pipkin saw in these stents.

So Steve thinks it's unlikely that these dents were created by another car, what he poetically refers to as a phantom vehicle. That's a vehicle that's alleged to have been present, but leaves behind no physical evidence. But he doesn't totally dismiss the possibility of a phantom vehicle. He zooms in on the dents.

In the simulation, the phantom vehicle sideswipes Karen's car on the driver's side. Then they have to be parallel for a period of time.

Steve actually looked to see if he could find a car that would have been on the road in the early 1970s that had a bumper low enough to cause the kinds of dents we see in Karen's left rear bumper and fender.

I've always said we follow where the facts lead us. I was convinced that a close-up look at the bumper was going to unlock this thing. But in the end, that's not what I was hearing from Steve.

Steve says even if a phantom vehicle didn't hit her or didn't hit her hard enough to push her off the road, there's still the possibility that Karen was startled and then overcorrected. The intimidation factor.

So what does it all add up to? Steve says there's no evidence to definitively prove or disprove the presence of a phantom vehicle.

Two hours later, Steve pressed pause on his PowerPoint and opened it up for questions and reactions. People's faces were drawn. This didn't seem to be the definitive closure we were hoping for. There was this uncomfortable pause where no one said anything.

So maybe it was something else. Then Karen's daughter, Christy Riddles, jumped in. She asked a question I think a lot of us had.

What it comes down to, Steve explained, is that Karen lost control of the car. but we still don't know why.

Karen Silkwood's son, Michael Meadows, shared what I think a lot of us were feeling, this mix of gratitude, appreciation, but also some disappointment.

There was a chorus of thank yous and goodbyes.

We were hoping Steve Irwin, with his analysis of the bumper and all the other evidence, would solve the mystery.

I think it's fair to say that's what Karen's family was hoping for, too. Confirmation of a second car or, at the very least, some definitive answer to why her Honda Civic left the road and crashed into a concrete wall as she was driving to what was arguably one of the most important meetings of her life.

It turns out that while technology can do a lot of remarkable things, at least in this case, firm answers weren't part of the deal. At least, not yet.

The day after our session with Steve, one of our producers got a text from Karen Silkwood's older daughter, Christy Riddles. Christy was eight when her mom died. She was the oldest of the three kids and the one with the most memories of her mom. Christy was the one on the Zoom call who asked if Steve could pinpoint why Karen lost control of her car the night she died.

Unfortunately, Steve couldn't give her that piece of the puzzle.

Karen Silkwood did play a role in raising awareness about the risks and dangers of nuclear power.

About a month before she died, Karen told the union leader, Steve Watka, that she was going to be gone from Kermagee, and that she was going to shut things down before she left.

One of those workers was Jim Smith. He'd been a manager at the plutonium plant from day one. He told some documentary film producers that before everything closed down, there'd been talk of Kerr-McGee re-upping their fuel rod contract. But that would have required a major cleanup effort.