I think if you add the reports together, it makes sense. To me, it sounds like the officer realized that they matched the BOLO description just before he stopped and came back: (note the bolds I made)
1. " Police Chief Thomas Jackson said the officer who fired the fatal shots, Darren Wilson, did not know Michael Brown was a robbery suspect when he
initially stopped the teen and a companion "because they were walking down the middle of the street blocking traffic."
Jackson told the St. Louis Post-Dispatch that Wilson
knew there had been a robbery in the area but did not know that Brown was a suspect."
http://www.cbsnews.com/news/darren-...er-who-fatally-shot-michael-brown-identified/
2. "The officer
drove away but stopped and backed up , almost hitting the pair, Johnson said. He said
he wasn't sure what prompted the officer to return. (...)
"We were so close, almost inches away, that when
he tried to open his door aggressively , the door ricocheted both off me and Big Mike's body... "
http://www.cnn.com/2014/08/14/us/ferguson-michael-brown-shooting-5-things/index.html.
3. Ferguson officer
realized during encounter that Michael Brown might be suspect in robbery, chief says
The officer who shot Ferguson teen Michael Brown stopped Brown and another teen because they were walking in the street, not because of a robbery a few minutes earlier, Ferguson Police Chief Tom Jackson said Friday afternoon.
Jackson said the officer was
aware cigars had been taken in the robbery of a store nearby, but did not know when he encountered Brown and Dorian Johnson that they might be suspects. He stopped them because they were walking in the street , Jackson said.
ButJackson told the Post-Dispatch that the officer, Darren Wilson,
saw cigars in Brown's hand and realized he might be the robber. "
http://www.stltoday.com/news/local/...cle_52c40b84-ad90-5f9a-973c-70d628d0be04.html
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I would guess the officer also took notice of the clothes and size of MB.
So IMO, the pieces fit if we add the reports together.
