People are always shocked at the stupid mistakes that big criminal masterminds make.

Like the Silk Road guy, "how could he possibly ask on stack overflow using his real name".

And so on.

There are ten thousands different mistakes that you can make, you need to guard against all of them. And against whatever unknown tech exists.

In this story, that dropped bank card turns out to not be that significant. The real breakthrough was identifying another mule through the video surveillance videos, following him to the airport and putting surveillance on the lockers used to store the cash.

He was also emptying ATMs apparently with witnesses behind him. This is like a bad movie. One of those witnesses might as well be an off-duty cop who could just pull out his gun right there.