You wouldn?t be stretching things in an attempt to make your point more valid, now would you?
Of course he would.
Markham tells us in her testimony that she left home on 9th street "at a little after one". She only needed to walk two blocks (a distance of about 0,2 mile or roughly 4 minutes) to get to the bus stop at Jefferson. In her testimony she added "I wouldn't be afraid to bet it wasn't 6 or 7 minutes after 1" but even if that estimate was spot on, she still would have arrived at 10th/Patton at around 1.10.
So, in order for her to witness the shooting of Tippit on 10th/Patton at 1.15 pm she would have needed the better part of at least 5 to 10 minutes to cover the distance of one block. And even then, it doesn't add up, as Markham estimated that she usually catched the bus at 1.15 pm, which means that she still could not have been at 10th/Patton to watch the shooting at that exact same time!
However, the bus schedule for Markham's bus allegedly gives arrival times at the Jefferson stop as 1.12 and 1.22. I say "allegedly" because I have never seen a copy of the schedule. Anyway, in order to desperately get Markham at 10th/Patton at around 1.15 pm Bill Brown dreamed up a scenario in which Markham didn't catch a delayed 1.12 bus (perhaps he thinks no busses were ever delayed in those days) at 1.15 but instead (according to Bill) she really took the 1.22 bus every day.
The problem remains of course that Markham said she left home "a little after one" to walk two blocks in about 4 minutes to the bus stop. So what was she usually doing between 1.06 and 1.22, on those days when she did not witness a murder at 1.15?