Just watched the fight again. Poirier is right, he was able to check Conor's kick. Twice, too. First was with his knee in the beginning of the fight (notice Dustin even gestures to it immediately after).
And one more with his elbow just before the tibia broke; probably unintentional.
Either one could have started the fracture in the tibia which eventually caved when McGregor tried to twist his lower leg for a punch.
Sent using Tapatalk