xray t2 belt twisted and caught on spur area

[nivlacf1]

just would like some advice here, the lad was running an xray t2 his belt after a race twisted so i rolled it round and un twisted it, went on to next race all good and fine, next race his belt had twisted and caught in the spur area stopping anything from moving forward i got it untwisted out of the spur area it was stuck in and on he went(took some time to get it out) what i would like to know is why would this happen? does he need a new belt ? some one said i can tension it but i looked they looked and no one seemed any the wiser, any info thanks guys