I´m no expert but I don´t recall the report being very specific.
One interesting point is that the G-Data package combines Bitdefender with Kaspersky - probably set up differently which might explain why no conflicts were reported, but interestingly in this test, and I think some others, the Kaspersky suite alone "performed" best.
Remember that the test factors everything including price when the rankings are decided.
Maybe I can find out something more...but don´t hold your breath.

By the way, I depend on the Free AVG 7.5, combined with Zone-Alarm, Ad-Aware or SpyBot run daily, and a couple of other check-ups from time to time.