The 15-year-old suffered fatal knife wounds yards from his home in Merry Hill, Wolverhampton, on May 29, 2018.
Four 19-year-old men are accused of murdering Keelan: Brian Sasa, Tyrique King, Zenay Pennant-Phillips and Nehemie Tampwo.
Keelan was sat in a taxi with a close associate and the driver of the taxi just before 11pm when the group pulled open the rear door, which momentarily protected him, and set about him with weapons, Wolverhampton Crown Court heard previously.
Mr Jerome Lynch, defending Pennant-Phillips, said in his closing speech that the window was open when the attackers arrived so his palm print could not have been put on it on that occasion.
He said: "The case of the prosecution is the fingerprints and the palm prints are on the car because he was one of the attackers.
"The defence case is the prints are there because these are taxis he uses all the time.
"If the window was closed when the attackers approached the car the prints wouldn't be positioned where they are.
"If the window was partially open it's difficult to see how it would be possible for the driver to have sustained the injuries to his left hand.
"We're saying the evidence points away from it being partially open at the time.
"The driver said the window was fully open when the attackers approached the car, if that is true it is impossible for the palm print or finger prints to be positioned there.
"If the window is down you can't touch the window, there's no window to see.
"The witness said the window was open so it was placed there on a previous occasion."
Mr Lynch also denied Pennant-Phillips was in a gang.
"What's the evidence that he was a member of a gang? Clearly he had friends who were, he associated with these friends," he said.
"Of the thousands of pictures on Tampwo's phone, there's one of these four, and one of him with two others.
"Sasa is a cousin of Tampwo, King's number does not feature on Pennant-Phillips' call records nor the other way around."
Mr Lynch also said there was no evidence of Pennant-Phillips being involved in drugs, there was no evidence he listens to drill music, and there was no evidence of him ever carrying weapons.
Sasa, of Long Ley, Heath Town; Tampwo, from Fern Grove, Bletchley; King, of Chelwood Gardens, Bilston, and Pennant-Phillips, whose address cannot be published for legal reasons, have all denied murdering Keelan.