Can I noise hang a ColdFire forever...?

Hi people
I´m using a 5213 target and it hangs up after a turn off a close 12V/35mA relay wich doesn´t have freewheling diode, that is, generating a noise.
I´m using watchdog and others interrupts in order to make it resets, but "sometimes" it is not enought, the cpu
simply stops and only by a hw reset it turns to work back.
I´m not concerned about the reset issue,but about the hang forever detail....reset after noise is acceptable e expectaed, but hang up ...never...:(:( ??
My question:
- Is ColdFire able to "allways" reset after a disturb (conducted or induced)?or should I use a external watchdog?Some special care to assure reset allways?
Thanks
Ricardo Raupp