Since it's the other person who was frozen, I think it's safe for you to continue attempting to trade your pet (especially since you say that your pet is legit).
My only legit UC . got trade reversed the third time ... I had once which I traded my illegit UC faerie and got reversed , frozen . So I stopped trading illegit pets and trade my only legit UC try get a UC darigan Bruce . either ways , trading is getting harder and harder . Ahh feel bad ... Everytime You think You are about to reach the goal and then few days later bam ! Gone ... My UC is back and the other party frozen . Is trading off even possible now ? Anyone else have trade reverse problem ?
Since it's the other person who was frozen, I think it's safe for you to continue attempting to trade your pet (especially since you say that your pet is legit).
I would assume that usually, that sort of bought UC is more difficult for TNT to identify without more proof that it was bought instead of simply given away (since there would have been no sudden change in IP/password/pin/email prior to the UC being moved).
However, it is really up to you whether you want to risk it or not. No one can say for sure about what TNT will do.
Trading in the PC is just a nightmare, the UCs floating there are always the same and as soon as a new one appears the trade will most likely get reversed. There's a thread here of UC swaps and trades, I've had better experiences trading UCs with other clraik members than with PCers