GST or service tax? transition phase.

ABC co. India was fraudulently using brand of one US firm.So, they filed civil suit in indian court and won. And indian company has paid damages to overseas firm recently in GST era. The indian company is ready to pay tax as this service is covered as declared service under section 66E.
Question is whether recovery should be made under service tax or GST?
As payment was made in GST era, Point of Taxation Rules are not valid. Also taxable event seems to have occurred in GST era. Hence, recovery should be covered under GST provisions and not under service tax rules.
Expert comments, please.
The qies