When you are talking about large molecules like biologics (antibodies, most vaccines, etc.), there are a whole bunch of other things that can go wrong, but not this.
For protein based drugs there are prions: misfolded protein isoforms able to catalytically convert correctly folded proteins, basically following the same logic as the examples of smaller molecules. So far I guess we only know of one group of proteins that do this (like the mad cow disease one) but theoretically it could always happen to others we just don't know about yet. :)
Sorry if that made anyone feel worse again..
Yeah, they're selling this as a sustainable reaction because the second product is apparently formic acid instead of CO2. But of course that means less hydrogen per molecule of methanol and the efficiency using sunlight also seems to be low. So I would agree, sustainable in theory but absolutely nowhere near practical for anything.