You can choose exactly which input you want to spend and consolidate them. It also allows you a better control over your privacy, because if you just consolidate all of your inputs all your addresses will be linked together.
It's most likely all inputs from certain pool belongs to the single address. If he mined on different pools he probably has several such addresses with plenty of inputs. Then, he might probably try to consolidate (in a few tries) those UTXOs separately, starting from one address and moving to the next when finishing.