Yes,
Ross assisted me with a workaround. First I make an export of all othercontacts in my org that match an emailmatchpattern value.
gam config auto_batch_min 1 num_threads 20 redirect csv ./othercontactslist.csv multiprocess redirect stdout ./listothercontacts.txt multiprocess redirect stderr stdout ou_and_children_ns / print othercontacts emailmatchpattern ".*@domain.org"
For some reason the addition of a query at the end of this command will only produce ten results per user. Omitting it will provide all of the results. I've taken the export from this command and ran this command against it to delete the other contacts one by one. It's slow going and tends to overload the People API, but I'm finding success with it.
gam config num_threads 10 redirect stdout ./deleteothercontacts.txt multiprocess redirect stderr stdout csv ./othercontactslist.csv gam user "~User" delete othercontacts "~resourceName"