Yes, you can make excuses for why such a situation might exist... but why does the scene exist? What story elements does it provide? What character motivations does it provide? If, as you say, there is no follow up and no plot elements linked to it specifically being Gaius and Starbuck... then why was it Gaius and Starbuck? Either for no reason, and it's bad storytelling, or it's shock value, and it's bad storytelling.