Job interviews are almost always "unfair" anyway - they have a mass of applicants and there are always a lot of qualified people with no reason to select one over the other. The "hum a tune" bit is especially bullshit, since you said this was a software related job.
This is super ok, trust me. While it probably wasn't wise to not prepare your lies, you didn't do anything wrong. These people have the weirdest, most arbitrary expectations, and it's completely ok to tailor your CV or your interview towards that. You never lied about anything pertaining to the job at hand.
This is super ok, trust me. While it probably wasn't wise to not prepare your lies, you didn't do anything wrong. These people have the weirdest, most arbitrary expectations, and it's completely ok to tailor your CV or your interview towards that. You never lied about anything pertaining to the job at hand.