Complex sentence: While serving NASA Administrator Michael Griffin, Stadd told his NASA ethics advisers that he was recusing himself from any activities that might benefit his consulting clients, even as he subsequently billed his clients for his activities on their behalf while he had been at NASA.
Split into simpler sentences: While serving NASA Administrator Michael Griffin, Stadd told his NASA ethics advisers that he was recusing himself from any activities that might benefit his consulting clients. Nevertheless he subsequently billed his clients for his activities on their behalf while he had been at NASA.