Is this fair?

[ahecht]

Honestly, the fault here lies entirely with the referee, who didn't show any gracious professionalism. The fact that your inspection sticker wasn't signed could only mean one of two things:

a) Your inspector forgot to sign your sticker before giving it to you
b) Your team stole the sticker from the inspection table

Since he wouldn't let you play, basically the Ref was accusing your team of theft and of violating the spirit of the competition, which is a very serious charge. Something that could DQ a team from competition. The ref should have let you play the match while the inspection sheets were being checked, and then DQed your team from competition afterwards if it turned out you had stolen the sticker.