wrote:

But in that case the captured proton decays to a neutron.
I wonder if some proofreader thought "neutrons decay to protons, not
vice versa, so let me correct the text" without thinking that in the
high energy state we're talking about electrons and positrons and gamma
rays are flying all over the place providing enough energy to push a
proton up the energy hill to "decay" to a neutron?

There's no need to resort to 'electrons and positrons and gamma
rays [...] flying all over the place' here. If the binding energy
of the neutron is sufficiently greater than that of the proton,
the decay of the proton to a neutron (with emission of a neutrino
and a positron) is energetically allowed.

Nuclei that decay in this way are used every day in Positron Emission
Tomography (PET). A typical one is 18F, which decays to 18O.

Paul