Pitch-angle distributions of protons recorded by Wind/3DP at 4 MeV (panel a) and STEREO-A/LET at 6 MeV (panel b). The panels include: (i) the measured intensities within each instrument’s field of view; (ii) the pitch-angle coverage, displayed for the eight angular bins of Wind/3DP (a) and the central angles of 16 STEREO-A/LET sectors (b), with front-facing sectors shown in red hues and rear-facing in blue hues; (iii) a colour-coded representation of the pitch-angle intensity distribution; and (iv) first-order anisotropy values, ranging from −3 to 3, following the approach of Dresing et al. (2014). A vertical line marks the timing of the soft X-ray flare peak (approximately 09:44 UT), which is linked to the associated SEP event. Details given in the main text.