I use JER-LGW occasionally, and the last time I do remember a very long tedious trudge to get to Domestic reclaim. No idea of the details, though, I just followed the herd, as the OP said, from the front [1A/B] to the rear doors and beyond.

Reclaim has always taken what seems like ages, for some reason. I invariably have time to leave the domestic reclaim area, use the Gents hidden round the corner, say hello to the driver who is waiting for me, wander back to the carousel ... and wait some more. Typically 15 minutes or longer.