legally speaking.. a contract should be formed once
there is an offer (which was established by the seller offering a price to his lens to the buyer directly) and the buyer communicates his acceptance (which was shown when he agreed through SMS to the buyer).
that's how i would see it. And by right, i would think TS has every right to bring action against the seller for a breach of contract. I'm not studying law, so dont quote me fully on this, this is just what i read on business law.
Although, on the other hand, i dont know whether bringin such small matter up to court is worth the money. HAHA. okay, just my personally opinions.