I'm not seeing it as a jump or advantage. If we can put out feelers before firing our head coach, chances are the other teams did the same thing. So the Texans interviewed a man who has a good idea which teams are interested. The Texans obviously left that interview feeling that O'Brien is ready to take the job.
The only thing I'd worry about is if other teams contacted O'Brien since they heard he is our leading candidate & O'Brien has a better option available to him than he did at the time of the interview..... say Pittsburgh decided it's time to move on, so they send word to O'Brien's people that they want him. Or Belichick decides to step down & identifies O'Brien as his heir apparent. Those kinds of things can change the landscape & Houston most likely won't know until Tuesday. Unless O'Brien is a stand-up guy & he calls Bob (because Rick is obviously taking a back seat on this decision) & hints that he has other options he needs to weigh.
On the other hand, Wisenhunt will probably be interviewed because O'Brien left the Texans with the understanding that he wants to wait & see what other options present themselves come Monday.
With that in mind, if their top prospect ends up being the guy the choose, I'm fine with what has transpired so far. If not, then I'd like to see the Texans talk to the Seahawks DC or the Bengals DC before making up their mind.