Tech trading isn't as much of a confirmation as doll seems to think it is. There are hostile alien roles, and doppelgangers could pass on tech if they're in contact with an alien.
I considered this possibility when I first saw the claim by TDS, but both of these are edge case scenarios. Assuming that TDS is able to pass tech, meaning there was more than one small slot item that was his, there are only a few aliens it could be. Let's break them down:
Xenozoologist: Would be playing against their win condition and may be unable to win at this point, with two psionic humans dead. There have been no abductions to this point, so there's no reason to believe one would exist, much less work with the scum team.
Exterminator: Would be playing the long game and taking a huge risk, since giving additional information to the town helps them find the scum quicker. If all scum are lynched quickly, with many town alive, and the game doesn't end, who better to lynch when the killing starts than the claimed alien?
Exterminator Operative: If this role is actually in the game the game is probably already lost for the town, with five anti-town roles and two parties with kills. Almost certainly not the case, and see the exterminator section above for more reasons why it's unlikely.
Agent Operative: the claimed role, nothing unusual here.
Hivemind: The highest probability among the anti-town roles, and is a rather terrifying threat, especially because it's possible the entire thing is a ruse to keep their converted ally from being lynched and revealing their presence. A possibility, but I'll detail a way below to show how to rule this out.
Mind Stealer: See the Xenozoologist section above.
Now, what of the case where the scumteam got tech from a third party? Let's assume for a moment that TDS is able to pass tech, meaning that they weren't in contact with a survivor who for some reason decided to pick up scanner instead of a defensive item (a risky play, but not one that can be entirely ruled out). The real question is, though: what alien role would actually do that? Only an exterminator who was playing a long game, but what would they claim? They can't claim survivor, since they'd have passed more than one piece of tech, and all other tech-using aliens are hostile to the scumteam as well. So it's unlikely they got multiple pieces of tech from an alien if TDS is scum.
Now, how do we rule out hivemind, the most likely of the situations detailed above? It's simple: if we can pass tech during the day, TDS passes the tech to someone he considers trustworthy, who will in turn pass the tech to someone they consider trustworthy, and who in turn passes the tech to someone they consider trustworthy, who can then pass it back to TDS. Since a hivemind will only have had the time to convert two people, at least one of the people is guaranteed to be clean. If
any of them claim to have not received both a medium and small tech item (which is a combination a hivemind could not have) we lynch TDS immediately. If TDS is as he claims to be, a scum has just outed themself and we lynch them the next day.