MUTEX-skiplist does not work properly with the -A (alternate) test option

When running:

./bin/MUTEX-skiplist -t 64 -u 20 -A, we freeze forever due to the following runtime errors.... i would assume this has to do something with the way the -A option is handled in the test rather than the correctness of the data structure

TARTING...
Error 22 from 11 cannot unlock node[2]:106543718
Error 22 from 11 cannot unlock node[2]:89834423
Error 22 from 11 cannot unlock node[0]:1135056668
Error 22 from 11 cannot unlock node[0]:154808587
Error cannot lock pred->val:754493014
Error 22 from 21 cannot unlock node[0]:151884419
Error 22 from 11 cannot unlock node[2]:754493014
Error 22 from 11 cannot unlock node[0]:156777624
Error 22 from 21 cannot unlock node[1]:336645300
Error 22 from 21 cannot unlock node[0]:1929152689
Error 22 from 11 cannot unlock node[0]:361432084
Error 22 from 11 cannot unlock node[0]:1162105697
Error 22 from 11 cannot unlock node[0]:809614975
Error 22 from 21 cannot unlock node[0]:830086315
Error 22 from 11 cannot unlock node[1]:832822539
Error 22 from 21 cannot unlock node[2]:893453624
Error 22 from 11 cannot unlock node[0]:1756269622
Error 22 from 21 cannot unlock node[4]:1710976125
Error 22 from 11 cannot unlock node[1]:921212005
Error 22 from 21 cannot unlock node[2]:835181202
Error 22 from 11 cannot unlock node[2]:805278814
Error 22 from 11 cannot unlock node[1]:1534167311