You don't. No one can really say what's going on at Gox besides karpeles and his cronies. The market is losing faith in Gox, and the lack of arbitrage opportunities only exacerbates the spread between Gox and other exchanges.
True we all can't say 100% we know what is going on at GOX, but we can use all of the tell-tale signs to deduce what is very likely going on over there.
Any person/business when accused of being insolvent and is not insolvent would be screaming out to the media and community they are solvent and then provide PROOF they are solvent. (which can be easily managed if they aren't insolvent).