TM breakers with trip because of an overload in response to I2t or magnetically (instantaneously). The must be current maintained for a given amount of time to fall within the thermal trip curve of the breaker in order for the breaker to trip thermally. If you were tat the breaker location when the breaker tripped more often than not the breaker can not be reset, latched and closed immediately as the thermal element must cool.
The magnetic element is often calibrated 7-10x the breaker rating for residential breakers and 10x for commercial and industrial breakers +20%. This means that a common 20at breaker would be calibrated at 200a but most likely is calibrated toward the high end at 240a. This means that a 20at breaker must see an instantaneous current of over 200a for it to call for a trip.
The question is if in fact the breaker saw 200+ amperes. Since the scenario as described was most likely resulted in an arcing fault it is highly doubtful that the breaker saw enough fault current to trip.
Such a situation is common in that we expect a breaker to trip. Because the breaker doesn't have eyes to actually see when we can, the breaker can only respond to the current values that it has been designed to respond to regardless of what is or has happened down stream on the circuit it protecting.
Since arcing faults often are L-G or end up to be so within a very short time a GFI breaker will with almost all certainty would have picked up the fault and opened the breaker.
