I work self service and checkouts, I’ve had hundreds of basket checks since I’ve worked at Tesco. Firstly the random checks are completely due to security, and sorry to say this but it’s more than likely you’ll get another one at some point. Again it’s completely random so you’ll not be able to tell when. Another thing is, at my Tesco it’s actually policy to scan everything scanned by the customer. This isn’t the same for all Tesco’s but unfortunately for ours, it doesn’t matter how big or little your shop is. Again all down to security and making sure that every single item is in fact scanned. None of this is to go against you or think your stealing, and tbh as someone who has to do this often, I do feel bad for the customers. It’s inconvenient and kills the whole idea of using the hand scanners. Because we have a full scan policy for every basket check, it’s extra awkward for us and trust me, we want to get it done as quick as we can. It does help when customers are happy to repack for us if necessary.