Yep, that's a massive argument against Donut. But the question I haven't seen the battery experts address is whether the expansion pattern is unique to the chemistry they believe it is. Are there other chemistries that could produce the same effect? The investigators clearly don't think so, but Donut also isn't claiming to be using previously seen tech.
Either way, it's not looking good for Donut. The burden of proof is, and always has been, on them, and they have a looooong climb out of the hole they've dug.
Regardless, Ziroth and others make a good point that Donut's marketing games are damaging to the industry. Other legitimate players seeking investment will be tarnished by Donut's antics. So even if their tech turned out to be legit, they're still going to be a bad actor.