My own anecdotal experience is that this can happen to cheaper tubes after a few years but have had better quality one such as Michelin last a lot longer. I of never had a blow out as a result of the tube degrading but have had them become porous resulting in a slow puncture.

That's bad luck for the old fella in NZ. Stuff happens.
The "new tire, new tube" theme has been around for decades ... and it's good advice. But the fact is ... few follow it. Especially riders out in Bum-f##k Bolivia with no tubes for sale in a 1000 miles.
Out there ... Tubes are GOLD!

Here is the thing with tubed tires:
1. When a tube is punctured it can often deflate pretty much INSTANTLY.
this is of concern if traveling at high speed in a turn or on a crowded motorway. Sounds like this is what got the old boy on the F650. Your bike can get out of control quickly .. before you have a chance to react and get off the road. A tiny hole may not do this ... but a good size nail will ...I know because I've had it happen several times to me.

What to do?

2. I use either SLIME or Ride-On in my tubes. This is not Fix-a-flat, it's something a lot better. It's goop you put it in ahead of time and leave it in. It can prevent a puncture by sealing up the hole ... in some but not all cases.
Overall, it works pretty well but breaks down over time (over a year)

BUT ... what it most ALWAYS DOES DO ...is to slow air loss. This gives the rider a fighting chance of realizing he's got a flat and pulling off the road safely without binning it. So that there is the life saving part of why I use it.

SLIME and Ride-On are sold in USA. No idea whats on in Oz or NZ. But the stuff WORKS and will save your life.

3. Natural rubber tubes tend to last longer than Butyl tubes. YES, they are more expensive ... I also find they are easier to patch and they last longer.
Patches won't stick to some Butyl tubes. (synthetic rubber)
One caveat ... with SLIME in tube it's hard to patch a hole, you have to wash off ALL the SLIME for the patch to stick on the tube. Not sure about Ride-On.

When on the road for weeks or months ... I carry 3 spare tubes on board.

A few times I have seen tubes that split for no obvious reason. Rare, but I witnessed it so I know it happens. But mostly the split is from a puncture ... which can sometimes cause a split if it's an old, dried out tube.

Ride Safe!

Slime? yucky stuff! I much prefer Ultraseal.
For some £5 IMHO, it's a false economy not to replace inner tubes at least once a year.
I change mine once a year usually when prepping for a trip. The more expensive part, but worth it for me, is replacing the Ultraseal.
(which is water soluble btw so- albeit a slow process, you can wash out a punctured inner tube if needs must.)

__________________
I do not list my vehicles or the places I have travelled to nor do I live my life seeking validation from others.

Do you really change your tubes once a year ? I usually do it when either I change the tyre or I get a puncture and the damage is beyond what's safe for a patch. No critisism, just interested in different people's practice.

Where do you get your £5 tubes from btw? Most of the tubes I've bought recently have been two or three times that. It's probably why I don't bin them so frequently.

Bertrand,
I think you may have missed my point ... which was that the use of any sort of Anti-deflation product is better than NONE. Anything to slow air loss ... that is my point. Slime, Ride-On or Ultra-Seal ... all good!

Me thinks you've never actually used SLIME ... I first used it riding Baja and Copper Canyon in 1998. And guess what? ... IT IS water soluble and always has been. BUT ... Ride-On is the better product, but more expensive.

We don't get Ultraseal here ... any good?

The GOOD thing about SLIME is that you can see little green dots on your tire when you've run over something. (Like Cactus thorns or small nails) The green dots are Slime coming through the tire ... filling the nail hole. Nice to know it's actually doing it's job!

Totally agree regards starting off a big ride with NEW tubes. But once out on the road for a while ... sometimes you are only left with what you've managed to salvage or repair. (Been there, done that )

In certain countries you will not find quality, real rubber inner tubes ... only very thin, cheapo, Made In China ones made of Butyl synthetic rubber.

I have had both modern tyres and tubes replaced because of perishing. Tyres you can see easily. tubes not. I always carry at least one spare tube AND rim tapes.
Re the crash, If a front tube leaks slowly it will ride fine until it doesn't. at that point the bike becomes unstable and difficult to control. The tendency is to slow down which puts more weight on the front causing a feedback loop which can often be terminal.