Question: who was originally cast for back to the future
[{'answer': 'Eric Stoltz', 'provenance': [{'wikipedia_id': '699417', 'title': 'Eric Stoltz', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 11, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '699417', 'title': 'Eric Stoltz', 'start_paragraph_id': 13, 'start_character': 0, 'end_paragraph_id': 13, 'end_character': 824, 'bleu_score': 0.6591374026168011, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8344467990342437271}, 'section': 'Section::::Career.:1978–1999.\n'}]}]