Pedant's corner
"..hackers, had penetrated FireEye's servers and made off with its crown jewels: the tools it uses to test other companies’ defenses. Armed with those penetration tools, hackers could potentially identify which of their methods will pass FireEye's gaze undetected."
No. The tools will be things like scanners, exploit frameworks and standalone exploits for vulnerabilities, which they use to find and exploit those vulns in their pentest customers' networks. They don't have anything (directly) to do with FireEye spotting other attackers in action.
Biting the hand that feeds IT
