The only thing that happens if they say no is that they may be held liable later if the content is found to be infringing. So in a case like this, which is nonsense, they could just say "no" without any fear because nobody is going to find it infringing in court.
(This will likely surprise people or generate snarky responses, but oh well) Back when we had code.google.com, the DMCA team at Google used to spend a tremendous amount of energy and time evaluating requests to understand whether they were reasonable/made sense, because code.google.com got a lot of baseless requests to remove content.
Google said no to a large number of baseless removals.
Twitter could do the same here.
(in practice i assume the volume becomes completely overwhelming at some point)
The law is clearly broken but service providers like Twitter are caught in the middle.
As someone that had to deal with these reports, and we were tiny, the volume is insane. I cannot imagine the number of complaints Twitter receives.
I mean, humans are still involved in the process almost everywhere anyway, so it's not like they save a tremendous amount of overhead to flag weird ones.
"The law is clearly broken but service providers like Twitter are caught in the middle."
Sure, that i'm not gonna argue with
Now they have a convenient excuse for what they did.
As you said yourself, Google had a DCMA team...
They still do, and they still push back, fwiw :)