Speaking to the BBC for its Panorama programme, to be aired on Monday, the Met's assistant commissioner, Mark Rowley, defended the force's failure to follow the recommendation.
He said: "Perhaps some formal paperwork and formal thinking should have been done at the time – it wasn't, but we're constantly looking at the tactic.
"If anyone has a better idea on how you confront armed criminals in vehicles with a view to arresting them safely and seizing their weapons then we're up for better ideas. People say review, people don't come forward with better ideas."