  In previous work with Ken Wharton, it was proposed that Bell correlations are
a special sort of selection artefact, explained by a combination of (i)
collider bias and (ii) a boundary constraint on the collider variable. This
requires no direct causal influence outside lightcones, and may hence offer a
new way to reconcile Bell nonlocality and relativity. This piece outlines a new
argument for the proposal. It explains how it is valid for a special class of
('W-shaped') Bell experiments involving delayed-choice entanglement swapping,
and argues that it can be extended to the general ('V-shaped') case. A detailed
version of the argument is now available in arXiv:2406.04571 [quant-ph].
