The Batch no should have helped us a lot.
Normally this will happen if the wheelchair is pushed very hard with break on.
But having considered that, The PU coming off from the tire is the PU quality, which can be an issue. When we inspect the tyre by cutting we can be more certain of the quality of the PU of that particular tyre.
The reasons can be :
PU processing mainly due to a power on/off, just need to check the hardness of the tyre, if that is Ok, then normally PU is ok. This can be a very one off issue.
If there is a sudden power cut, the tyre under process that very moment can have such issue which are not visible till it is used continuously.
The PO no. suggests that this tire was from August 12 shipment. Only the batch no. can give us some more insight when we look at that particular shifts records.