Λέει is a smart way Greek vernacular language has to indicate something we haven't witnessed with our own eyes, or something we read: Είδα λίγο ειδήσεις στην τηλεόραση, θα έχει λέει καύσωνα από αύριο. Children also use it to indicate something that is within the reality of their game: Θα είμαστε λέει πειρατές και θα ταξιδεύουμε. Το γκαράζ λέει θα είναι ο ωκεανός.
In the thread you read, SBE had already talked of the English arguing that they were robbed every time they lose ('we was robbed'), as you guessed yourself.