If you approach it from the Negative Income Tax implementation then it's also much less to fund because basically the tax deductions already baked into the tax code can be made at some level into something that's sourced via UBI instead of just a floating deduction. Of the remainder, you fund much of that from some subset of existing social safety net programs.

It's not trivial, but I'd agree that the line was at best sloppy accounting, and at worst a dishonest criticism.