Why would you risk your job by putting your boss on loudspeaker if front of a client? Hardly professional. And given the emails were recovered using a Third Party tool, the same solution the Team Leader suggested initially before the registry idea, its actually a non story.
I'm surprised the team leader didn't sack you for making a stupid escalation call when you knew how to resolve the issue in the first place.
Stick to those Printers if PST's are too challenging without help from your superiors.