It appears that many (all?) entries in sentential_subject_island.jsonl have a spurious possessive as part of the subject. For instance:

{'UID': 'sentential_subject_island',
'field': 'syntax',
'lexically_identical': True,
'linguistics_term': 'island_effects',
'one_prefix_method': False,
'pairID': '23',
'sentence_bad': "Who have children' investigating alarmed Joel.",
'sentence_good': "Who have children' investigating Joel alarmed.",
'simple_LM_method': True,
'two_prefix_method': False}

{'UID': 'sentential_subject_island',
'field': 'syntax',
'lexically_identical': True,
'linguistics_term': 'island_effects',
'one_prefix_method': False,
'pairID': '32',
'sentence_bad': "Who were those governments' talking about astounding Jason.",
'sentence_good': "Who were those governments' talking about Jason astounding.",
'simple_LM_method': True,
'two_prefix_method': False}