Mann, ich bin eine Flasche...
Flasche = both bottle and loser? Is this more of slang usage?
You are correct. The colloquial meaning of "die Flasche" is "the loser". It does not get inflected with respects to gender.
Interesting. Maybe an indication of an alternative translation would help, sort of like the package icon on new words? It occurred to me the sentence didn't make sense but I knew of no other options.
Why would the put a colloquialism like this in the software? Was this unintentional or a joke from the programmers?