I once put an NPN BJT in a circuit inverted i.e. collector and emitter swapped. The base was floating and the C was connected to a resistor/capacitor in parrallel to gnd while the E was connected to +15v. The circuit oscillated as a sawtooth, at a few kHz. The E-B would break down injecting current into the B which would turn the inverted NPN on, and it would stay on until the current decayed to a certain level then the transistor would reset. I asked an old Prof why it didn't recover immediately when the voltage dropped below the E-B breakdown voltage and he pointed out that C-E breakdown voltage is current dependent. All those SOA curves for BJT's. So a B-E breakdown can have other effects.