These are false claims. The following compiles and runs fine with Fil-C, happily corrupting memory in a way that a safer language like Rust would not allow:
His claims about Fil-C being safer than Rust seem to hinge on Fil-C's ability to make safe-er an entire application stack, compared to a hypothetical Rust application that links to C dependencies which (currently) can't be compiled with Fil-C. This is true as far as it goes, but it's a far cry from justifying a blanket statement like "Fil-C is safer than Rust".