[The following is not legal advise. For legal advise you must consult an attorney]
'We feel like it's kinda lke karma for them for all the crap we've dealt with."
You're a smart guy Brandon.
You know if you have, in good faith, attempted to resolve this issue.
Karma would dictate you DO NOT BENEFIT from this situation.
Karma does not dictate you must accept harm.
A mediator would suggest allowing a predetermined time for orginal owner to regain possession. After that time, action can be taken regarding the items that does not benefit you.
Be aware, right or wrong. whoever has easy access to an attorney will make life ugly for the other party. You really don't want to go there.
Karma, when you mess with her, things go whacky.