AFAIK, the A1/G1 output native 24/25/30p over FireWire only, outputting interlaced through other ports. Seems that the updated models have a bit of upgrade:

"To complement the XH G1S HD camcorder's 24F frame rate mode, the model adds flags when outputting video through HD-SDI (which normally outputs 60i). These flags allow compatible hardware or software to locate the frames needed for removal during professional editing, resulting in native 24F video."

I don't know whether the original G1 added flags to 60i stream, but the G1S is claimed to do that. So, after all it seems that proverbial "pulldown flags" indeed can be added to interlaced stream. I thought what they can be added to progressive stream only as hints for interlaced devices.

What flags are these? SDI is an uncompressed link, right? So no MPEG-2. So the flags are not MPEG-2 flags, right?