That's a good point. Hawking has to have got it right.Must we trust that Hawking was correct? If micro black holes did not evaporate, then we would find it difficult to explain why we don't find micro primordial black holes everywhere, or to explain the genesis of all the elementary particles at the origin of the universe instead of genesis of primordial black holes. If there was a non-zero probability of two particles forming a BH in the genesis, and if that was irreversible, then why not all particles becoming BH? I view the absence of primordial BH as an argument that the two-particle BH event (if it exists at all) must be time reversible.
We get more energetic collisions right here on Earth (occasionally) and they don't form runaway black holes.