The problem with that theory is the LE would have spoken to this co-worker at the time, since they provide an account of what BD did that morning in their affidavit. It is worded as fact, not as what BD claimed, which means that they corroborated it. Since local LE appeared to believe that BD was "hiding something" there is no question that they would have carefully looked at any statements she gave to them at the time and corroborated it. If there was any untruth they would have pounced. If this co-worker is telling the truth, BD would have been in jail years ago for lying to investigators. Since she is not in jail we can safely assume that whatever she told LE at the time was corroborated.
I think this co-worker controversy stems from people getting confused between the day HD actually disappeared versus the day she was reported as disappearing. The coworker is talking about the day HD was reported as missing, and on that day SA drove HD to work, we already know that. No one to the best of my knowledge has claimed otherwise.
If this co-worker is going to provide a "new" statement, it means that they one they provided originally was false (and they would have know it was false at the time since it happened right then), and that in turn means they could go to jail for obstruction. So, no new statement is going to be provided, unless that person is stupid and metaphorically wants to wear a "put me in jail" sign.
