It makes them equally liable. How much do you know about Hong Kong contract/consumer law? Yes your credit card protects you against them going bust but doesn't translate your rights to English law. If you've no rights there you've no rights against your card company
Well I've only spent 6 months practising Hong Kong law as opposed to 17 or so in the UK so I'll agree a lot less than I do about UK law
But its definitely a fair point.
However, post October 2015 the issue has been mitigated a lot by the Consumer Rights Act. That gives you a whole raft of basic consumer protection as to fitness for purpose, unfair terms etc. and, unlike prior legislation, applies to sellers outside the UK as well as just those within the UK / EU.
Now that's likely to be not a lot of use against Panamoz as you'd need to take a judgement to Hong Kong to actually enforce it - but it massively shuts down the likely arguments a credit card provider could use. Its also important to bear in mind that you wouldn't actually go after a credit card provider in court - much easier to go to the Financial Ombudsman who are entitled to go beyond a strict reading of the law and are generally fairly pro-consumer.
Of course this isn't legal advice because I don't know you and your circumstances blah de blah and there is a risk that it all ends up more complicated than going against a manufacturers UK warranty - but I wouldn't personally have a concern about the warranty position from Panamoz if I was buying on a credit card (though it would be worth printing off a copy of their Ts&Cs so you can clearly demonstrate to a credit card company what you were buying).
It does still leave open the ethical question mentioned by snerkler though - not to mention that if everyone used them we wouldn't end up with any camera shops in the UK which would be a shame (though one I'm less fussed about after buying from Calumet partly for that reason and then being repeatedly messed around by them).