Originally posted by DonsAdvisor:
Lou the driver is conveniently not around when Michael departs the restaurant - in both the novel and film. In the Corleone plan, a disarmed Michael exiting the restaurant was vulnerable to a potentially armed driver. The novel also has other Sollazzo goons sitting around, pretending to be innocent bystanders. These guys also froze in their moment of need. Tessio, who couldn't whack a fly, wasn't there to defend Michael. I find these point unsatifying with regard to reality of the plan.