What's the point of using one of those if only SD video can be recorded anyway?
No point. Your DP didn't know what he was doing and you got a DV recording on expensive tape. Here is the fact, it is a DV recording, not HD recording.
Perhaps he thought it was recorded as HDV on tape.
Panasonic was the only company to use memory cards to record at that level when they came out with teh camera. Basically they took a DVX100 and copied Andromeda who was already doing pixel shift, and simply made a new body, kept the DVX recorder, and the same chipset, and had a cheap, easy to engineer HD camera using P2 which was originally tried as a professional format for news ENG but didn't get the sales they were hoping for so they got their investment back by making it into a consumer/prosumer format into the HVX.