He oversaw the project, however, he was plagued with bad luck, as GDI had neither the knowledge nor the technology to tame the destructive potential of liquid Tiberium, resulting in over two dozen deaths of top GDI Tiberium researchers over time.
This led to his general unpopularity with GDI brass and scientific staff, as the results weren't satisfactory enough to warrant risking lives of top researchers. And hefty paychecks to those willing to work for De Groot didn't change a thing. Even his friend, Eliot Smith-Johnson, found himself unable to convince the top scientists to work for him.
All of this became a moot point when NodBlack Hand forces invaded the outback and sabotaged the liquid Tiberium research facility, announcing the return of Nod as a global power. The explosion caused by the destruction of the facility covered much of Australia with deadly Tiberium fallout, turning the Australian Outback into a Red Zone.