Train Conductor

I'm not sure if I was clear. If a critical exposure was chosen, explain why that was picked. So if I said "Ascending/Descending, falls from heights" as one of the given exposures present in the example, explain why you chose that. What's the proof that it was present in the example. Thank you in advance.

Fallen Worker - August 15, 2019 Location Summary Toronto, ON Conductor fatally injured when movement derailed Description The Conductor was working a yard assignment in Toronto MacMillan Yard. The employee had pulled a cut of 24 cars from track E008, onto the west pullback, stopping the movement north of the W100 switch. The Conductor then backed onto track W100 and coupled to the cut of cars consisting of 24 empty multi-level cars and 34 freight cars (26 loaded cars and 8 empty cars). While pulling the cars from track W100, a stringline derailment occurred, resulting in 9 cars derailing. Because of the derailment, 3 cars fell on their side, one of which the employee was riding. Applicable Rules 1. Transportation Life Critical Rule - Riding Equipment - 3-Point Contact Which of the following critical exposures were present? Line of Fire Pinch Points Ascending/descending, falls from heights Lifting, lowering, pushing, pulling Eyes on path Eyes on task Fallen Worker - August 15, 2019 Location Summary Toronto, ON Conductor fatally injured when movement derailed Description The Conductor was working a yard assignment in Toronto MacMillan Yard. The employee had pulled a cut of 24 cars from track E008, onto the west pullback, stopping the movement north of the W100 switch. The Conductor then backed onto track W100 and coupled to the cut of cars consisting of 24 empty multi-level cars and 34 freight cars (26 loaded cars and 8 empty cars). While pulling the cars from track W100, a stringline derailment occurred, resulting in 9 cars derailing. Because of the derailment, 3 cars fell on their side, one of which the employee was riding. Applicable Rules 1. Transportation Life Critical Rule - Riding Equipment - 3-Point Contact Which of the following critical exposures were present? Line of Fire Pinch Points Ascending/descending, falls from heights Lifting, lowering, pushing, pulling Eyes on path Eyes on task