Topbunk yes it was the short term forecast (and actual!) that changed quite rapidly. (In the space of 44 minutes).
I agree a 9 hour taf might not make any difference per se but my perception is they were more accurate short term.
In all my experience locally this was one of the worst forecast changes - the local airfield had launched quite a few a/c based on a good taf and then we suddenly found the conditions had changed and they'd hastily issued an amendment. Threat and Error Management?