Pretty harsh on Sagan, looked to me like cav and Sagan both wanted the wheel, Sagan was just a head of cav as Sagan was cutting the line. Gap closes fast, Cav and Sagan touch with cav hitting just behind Sagans arm so sagan goes to give a little flick of the elbow to nudge him off/keep balance but cav had already started to go down at this point so that's why it looks like the elbow extends so far as it didn't really seem to hit Cav. Rubbings racing but an extended arm is a tough call to make.
Pretty harsh on Sagan, looked to me like cav and Sagan both wanted the wheel, Sagan was just a head of cav as Sagan was cutting the line. Gap closes fast, Cav and Sagan touch with cav hitting just behind Sagans arm so sagan goes to give a little flick of the elbow to nudge him off/keep balance but cav had already started to go down at this point so that's why it looks like the elbow extends so far as it didn't really seem to hit Cav. Rubbings racing but an extended arm is a tough call to make.