I'm completely satisfied with their position. The Moosoft Development folks clearly understand that LeakTest is a good thing, and is not any sort of Trojan. I've heard about other vulnerabilities in specific firewalls, like ways that some Trojan horse programs might be able to shut them down or penetrate them. That's an excellent and important question. It deserves an honest answer.
Any program running in the system can do virtually anything it desires.
A Trojan horse program whose author has deliberately reverse-engineered the operation of a specific software firewall can, without question, interfere with and disable that product's proper operation. Therefore, if I wanted LeakTest to deliberately penetrate any specific firewall by reverse-engineering its operation, it could definitely do so. I have, therefore, deliberately defined LeakTest's boundaries to stop just short of taking that road. But it will decidedly not exploit any firewall-specific knowledge. That's an important, but different, problem.