After a short glimpse, it is hard to tell if the allegations are true.
With other short sellers, the story was easier to understand and verify,e.g. Chinese plane ticket sellers where it turned out basically impossible to buy a plane ticket. I also found the allegations against Wirecard in Hackernews plausible, since such a complex network of companies rarely has legit applications. But Lasertec Corporation, I don't know.
E.g. :"Sources indicate that customers – presumably Intel - who claim to use Lasertec’s EUV tool are secretly using its old DUV system instead; that TSMC is running parallel, redundant inspections with non-EUV tools and has reverted to the DUV-based inspection process it used prior to Lasertec; that the market window for actinic EUV mask inspection is rapidly closing, as the next phase in EUV is High NA, which requires an electron beam solution, as OPC patterns and sub-resolution assist features (SRAF) are smaller than 13.5nm and cannot be
detected with actinic EUV light – leading ASML, KLA, and others to develop multi-beam inspection tools for High NA masks that render the ACTIS tool obsolete."
A lot of claims, very little beef. And why should Intel "secretly" use other equipment? Are they a stakeholder in Lasertec? All the allegations are possible, but not convincing, as laid out.