I have to take issue with the term "frenzied flight". According to the cab driver he offered his cab to a lady and was willing to wait.
So you don't take into account his leaving the building immediately, beating on the bus doors in the middle of the street, while the bus wasn't at a bus stop, obviously panicking when the bus was stalled and got off and then jumped in a cab, and all you have a problem with is while Oswald was already in the cab and logically expected to stay there that he maybe offered a lady his cab? How does that negate the totality that Oswald wanted to get the heck out of there?
And don't forget that Oswald didn't stop at the rooming house but drove several blocks past, why would he do that?
JohnM