It cannnot be symmetric
Taker has the advanatage that he knows the secret for the hash.
LP has advantage of time.
Otherwise if the time is equal, the taker can withdraw LP’s funds and Refund almost at the same time.
(like double spending)
Second, if the taker is malicious he/she can place a lot of orders and have open positions for many hours ( good opportunity for arbitrage), but if he/she has short time window to withdraw and long period time penalty, then the taker has incentive to finalize the deal.
This is typical logic for classical OTC and traders have met this problems already - Counter Party Risk.