Target count mismatch using level-restricted tree and large geometry

The problem is shown in $28. Using a large geometry (75 armed starfish, 2 million particles) and a level restricted tree (068a5a4e), I get the following error when building the tree:

  File "/Users/matt/miniconda3/envs/inteq/lib/python3.6/site-packages/pytools/__init__.py", line 578, in wrapper
    result = function(obj, *args, **kwargs)
  File "/Users/matt/src/pytential/pytential/qbx/geometry.py", line 535, in tree
    assert (tree.ntargets == tgt_count_2), (tree.ntargets, tgt_count_2)
AssertionError: (911250, array(909311, dtype=int32))

Using a 65 armed starfish does not cause this error.