Zerg player should have rushed when he knew he had the edge. IE, when he had that roach in the expanded base and saw no defense he should have ran in there with everything he had. To take out that expanded base would have meant instant victory. Also, Zerg player should have expanded outward more, he seemed overly content with just two bases. As long as he guarded the entrance to the Terran base, he could have had 3 or more bases, and even if he'd had lost those, he would have had more than enough resources to recover.