I have always bought Seabrook crisps as they labelled all their crisps gf. Mistakenly my husband brought home Seabrook crunchies which he thought would still be gf, but they have a may contain warning, which for me is not a risk I want to take. I can't even find them on their website, but have contacted them to ask if this means the crisps will no longer be gf. I have told them they will lose a lot of business.
It just shows how easy it is to slip up, even with companies you have used for years.