Skimmed, but what I gathered is:

The plumb lines diverged a bit. According to Palmer this means the earth is hollow, and everyone except him is chocking it up to air currents. Clearly, they can be pretty significant at that sort of distance. Few have been able to replicate the results all, and most get the expected results (parallel, with room for jostling / air currents randomizing).

Feel free to correct me if I'm wrong. It's too much to absorb right now.