The USB host ports on equipment I've designed would in theory never do that, as there is USB overcurrent detection that would shut the port off completely when anything odd was detected and not turn it back on until reset. This is standard for computers, they normally all do much the same, as I've found out the hard way once or twice!

That said, I can easily see a cheap charger not having that amount of protection built in for cost reasons. Probably it only has a PTC resettable fuse at best, which is more or less fine most of the time. In a case such as this it looks like the goo that resulted from the spill was just conductive enough to allow significant current to flow without going over the limit required to kill the charger completely, at least for some considerable time. If it did have a resettable fuse, it probably just slowly heated up, went pop, cooled down, reset and turned the power back on, etc...

Or if they really cheaped out it's just a biggish low-ohm resistor.

The problem is that pretty much all main chargers nowadays are cheaply made to a minimum spec that's only just adequate, even from large companies. You can certainly get very good ones, but they're normally only aftermarket upgrades, not supplied with the equipment. I'm forever being given ones that have simply died with a request to fix them, on the basis that it "Cost ten quid, it must be repairable." People get annoyed when I tell them modern electronics, especially something you bought off ebay, are consumable parts with a generally short lifespan.

Although I am slightly surprised that the heat was enough to do that much damage from a liquid spill. Normally they electrolyse enough of the conductor away that the short clears itself quite quickly.

Possibly the problem is that it actually WAS a decent charger, and therefore could produce reasonable power for some time even into a cranberry-induced heating element! A cheaper one would simply have died quietly... Or simply exploded. Based on the ones I've seen supplied with raspberry pi kits, it probably would have done that even left completely alone

Note to self: Check conductivity of cranberry juice, especially when tacky