Middleton, who won the British GT4 championship in 2018, was set to take over from Imperiale Racing team-mate Alberto di Folco in the first of two one-hour Sprint Cup races but was clipped by the oncoming BMW M4 GT3 of Jens Klingmann which pulled into the box in front.
“The BMW was sort of on the limit [coming into the pits], trying to make up ground on us from the start,” Middleton told Autosport.
