Improved homological stability for configuration spaces after inverting 2

In Appendix A of his article on rational functions, Segal proved homological stability for configuration spaces with a stability slope of 1/2. This was later improved to a slope of 1 by Church and Randal-Williams if one works with rational coefficients and manifolds of dimension at least $3$. In this note we prove that the stability slope of 1 holds even with Z[1/2] coefficients, and clarify some aspects of Segal's proof for topological manifolds.