Если хотят докопаться....
According to authorities, at around 4:20 a.m. on October 28, the victim, a 58-year-old man was walking on a southbound A line platform at the 125th Street-St. Nicholas Avenue station in Harlem.
Police say the man was approached by the suspect, who attempted to engage him in a verbal dispute.
When the victim ignored him and did not respond, authorities say the suspect followed the victim, pulled out a knife and stabbed the victim once in the upper back
After the attack, the suspect fled out of the station to parts unknown.
Отсюда
Если хотят докопаться, то докопаются. Чувака порезали за то, что он не стал спорить с нападавшим. А тому, видно, хотелось "поговорить". Ну не стал говорить - пришлось просто так порезать