Sucks to Be Them

Doing some research, and came upon this quote from one article (note that they would have been the first person to come up with a lock-free resizable hash table):

After the initial design, it took us several years to establish the safety properties of the algorithm. We did this by means of the proof assistant PVS [23]. Upon completion of this proof, we learned that a lock-free resizable hash table based on chaining was proposed in [25].