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Wait...

Uses an example of cold-welding to set the premise for the talk.
Psych! - Example was not actually cold-welding.

His second example, the Galileo Jupiter mission, didn't explain why we *thought* cold-welding was a result of a malfunction, and I've no idea how that information would come about because the craft never returned to earth.

wtf? Are these shows really getting so bad? I had more respect for this guy.

Since I quite enjoyed the talk I'm willing to overlook that fact He did also have some good examples of actual cold welding.

NASA has an interesting lessons learned article about the Galileo high gain antenna failure, which also seems to be more nuanced than "it was cold welding" - http://llis.nasa.gov/lesson/492

p.s. I got curious about the reference to Gemini, and I'm not 100% sure but I think it might come from a 1991 paper "On-Orbit Coldwelding Fact or Friction?" by Dursch, H. & Spear, S. (Bibliographic Code: 1991NASCP3134.1565D) or else it's from the paper it references as ref 5 (I. Stambler "Surface Effects in Space", Space/Aeronautics, Vol 45 No. 2, 1966 pp. 63-67).

That paper gives the opposite impression to the start of Derek's talk, rather than cold welding being discovered around the time of Gemini, it was often thought to be a problem around that time but as he says later was subsequently found to be quite rare (Dursch and Spear found no actual cases of cold welding causing spacecraft issues, they were usually friction issues due to fretting or galling caused by loss of lubricants, but still recommended taking precautions to avoid coldwelding).

I expect more nuanced explanations and information from this guy, so maybe I was just not expecting his little switcheroo on the initial story.

It's not that I'm doubting the reality of this in the least, but I'd really like to hear about the experiments where they tested and confirmed this phenomenon. I guess I expect science to be supported by facts.

I get sick of the "We found this principle out. Isn't that neat? Just take our word for it." It wasn't that long ago where we said "Today we understand that Dinosaurs are giant, scaly ancestors of reptiles".
We're never approaching things with "All the evidence we've discovered suggests this to be the case about 'X'", which is absolutely the way we need to address all knowledge, because we're constantly proving old findings wrong and that's a good thing for improving our understanding of the universe. This tone is present throughout today's science as well, and grates on me every time I hear it. History has shown us enough that we will eventually prove it wrong, so I wish we presented findings that way to begin with.
/Marginally related tangent!

That is actually what this video is about: how people thought cold welding was a problem in space but it turns out it hardly ever is. That wouldn't make a terribly catchy title though.

A few more references would've been nice.