Has there actually ever been an accident caused by a tailplane stall on a jet?
Depends how you define "jet". There was a Viscount (turboprop, of course) that crashed in 1977 after a tailplane stall on finals to Stockholm: see
ASN Aircraft accident Vickers 838 Viscount SE-FOZ Stockholm-Bromma Airport (BMA)
The type had bleed air deice/antiice on the tail, but it had been ineffective because of low engine power during descent and approach.