A question about the 66th address of the puzzle transaction

[ee1234ee]

There are many people here discussing how the Bitcoin in the 66th address was stolen after the private key was found. I want to ask, how was it stolen? My English is not good and I can't quite understand it.
Is it true that someone uses a program to monitor the Bitcoin network, finds the data block of the payment transaction at address 66, intercepts the data area, extracts the public key, and then cracks the private key?
Could you please explain to the expert what the whole process was like? thank you.