The Grand Jury counts are interesting in that people seem to infer BDI from the charges, but it's important to place them in the context of when they were made. The Ramseys were preparing for Patsy to be indicted and the crux of LE's case centered around PDI. LHP said after she testified she felt certain they were looking at Patsy due to the direction the GJ investigation was taking. Most people working on the case at the time didn't consider Burke a suspect -- BDI was tabloid fodder at this juncture. I think there is something to the argument that the charges were written in a manner that left both parents open to being charged with her murder. The juror who spoke out on 20/20 under a condition of anonymity said they didn't know which person did what (just like the rest of us!). While it's possible the counts mean BDI it's also likely that the GJ felt one parent may have abused/killed her and the other knew about it and helped cover it up.
I think you've just become one of my favorite posters, because I agree with everything you've been saying, haha. But yes: they couldn't really prove which one was responsible for her actual murder and which one was responsible for the cover-up, so they left it "open-ended" so to speak. In addition (and I'll probably get my head ripped off for saying this), this may be the reason why the DA chose to not follow through on the charges: because the GJ couldn't narrow it down further.