Pandur can't sit on his line in that instance whether he tries to take charge of the situation or simply act as the plan B. He did try to clear it but he both misjudged it, and slipped. He's at fault for it. Ajayi does have more options though... At the point Pandur removed himself as a passing option he could have put the ball out for a throw in, he could have touched it wide for Pandur to run onto and then clear, he could at the very least have held his ground and got in the way of the attacker, but he just stepped out of the way and left it wide open to run onto. He wasn't aware he had a man closing it down is the crux of the issue, but to be fair to both of them when that ball comes through there's initially no Derby player anywhere near it - which also makes the whole thing a lot worse when you watch it back.
If Ajayi does play it safe and puts it out for a throw in there's no way Derby can take that quickly enough to cause us a direct problem. They took loads of long throws all night and we dealt with them pretty well. It's just one of those unfortunate things that we move on from, but Ajayi putting that out for a throw in isn't bonkers. What happened was definitely more bonkers. It's a combination of poor judgement from Pandur and poor awareness from Ajayi.