English's career was overshadowed by an incident on 5 September 1931 where he was involved in a collision with John Thomson, the Celtic goalkeeper. Thomson dived for the ball and his head collided with English's knee (not his boot, as sometimes claimed). Thomson suffered serious injuries to his skull and died in hospital a few hours later. The official enquiry found that the collision was an accident, and cleared English of any blame; a view which was fully supported by Thomson's family and all players from both teams who were on the field at the time. Nevertheless, English was deeply traumatised by what had happened to Thomson.