What the hell.. hindsight being 20/20 I'm thinking if they spent the extra 20c per bin on flame resistant plastic this wouldn't have happened. I don't see much flammable material other than that thing.
Any kind of fire suppressant system would not be that desirable as it could ruin all of the stock.
I doubt that would have been sufficient. In fact I'd be very surprised if it wasn't already the case.
If you look at the contents of the average supermarket trolley it's chock-a-block with highly flammable materials (paper towels, cardboard, plastic film...) and backed up by stuff that burns really well once the former has acted as a fire starter (cooking oil, cornflakes, bread). Heck, if the Ocardo warehouse holds the same things as my local supermarket then there are cans of butane gas, boxes of matches and actual packets of fire-starters backed up by lots and lots of bottles of whiskey, gin, vodka... With those as a given it looks like an environment that's nigh impossible to properly fire-proof. All it's going to take is a spark in the wrong place, or a gob of sufficiently hot melted plastic hitting the wrong material (fire retardant plastic still gets hot, melts and even smoulders) and poof! up it all goes.
I think the only option is a VESDA (very early smoke detection) system that removes all power from the place (including remotely popping isolation relays on the robot batteries) backed up by a heavyweight fire suppression system that fires if the power cut off is ineffective. It might well ruin all the stock, but that's better than the stock, the whole system and the building going up in flames. Cleaning up has got to be better than rebuilding from scratch.
If they didn't already think of it, kitting out a few robots as localised fire fighters would be a good idea. Having them scoot to the location of any detected fire and start spraying fire suppression chemicals over a limited area would probably stop a fire spreading and limit the clean up to a comparatively small area.
And it would give the lady robots a source of jpegs to pin up on their scheduling tables - "Mr February, he may be small, but he packs a lot of watt-hours into his battery and has an impressive fire suppressant nozzle".
Edited to add:
Just reading the fire brigade (short) report. They did have VESDA, it failed to detect the fire - no information in the report as to
why it failed. Fire was detected visual by a human 30 minutes after it had started.