Why this absolutely ludicrous dispute over whether W and Mrs VD danced? That should be easily confirmable by interviewing those at the club...and might they have MORE THAN DANCED, such as in the parking lot etc? Perhaps her intent at the club was to collect samples that could be planted at the crime scene (hair and other) - let's wait and see what evidence the SDPD comes up with before continuing this line of thought.
A viewing of the movie GATTACA might be recommended at this point.