I've encountered what I assume is a programming bug.
Halfway through the adventure, the "USE" button disappears from below my inventory. This makes doing things like
SPOILER
finding the hidden locker
END SPOILER
impossible!
I have continued into the Golden Crate from the previous installments, if that makes any difference.
I've fixed it now. The USE button is meant to disappear at that point (to stop you switching weapons) but it now returns immediately after the DOG-BOT fight. Thanks for pointing this out.
So there is an article in Ryan's Gig Guide about the numerous times Diamond Head have been invited on stage with Metallica. There was a comment about how if there wasn't a Diamond Head there wouldn't be a Metallica. And how if there wasn't a Metallica there wouldn't be a Diamond Head second career phase.