If a possibility cannot be ruled out should it be then regarded as inevitability?

If you want the possibility to manifest, then yes.. 

Neciessity is its own law -- say the moralists. The possiblity and inevitablitly have reference to YOU.

No, possibility is not inevitability.

Even after an event has taken place, that conclusion is not inevitable. Remove, or change, one factor from the event’s progression and the conclusion changes.

Inevitability would imply that no matter what takes place, the conclusion is always the same.

Example, if a man crosses a road blindfolded, it is not inevitable that he will meet with a car accident. If he crosses the road when there is heavy traffic, there might be an accident. If he crosses the road when there is no traffic, he will not meet with an accident. The factor of traffic on that road has changed and the conclusion changes with it.

If crossing a road blindfolded will inevitably lead to an accident, then that man would meet with a car accident whether the road has heavy traffic or no traffic.

No, that is a false notion.

No, that doesn't make it inevitable.

Not at all as it may be just one of a number of alternative possibilities and as such is not inevitable. 

It's one of the potential options.  

We defy augury. There’s a special providence in the fall of a sparrow. If it be now, ’tis not to come. If it be not to come, it will be now. If it be not now, yet it will come—the readiness is all. 

Hamlet, Act 5 Scene 2

Only in an infinite time line. Otherwise, no. 

No - what makes you think that?

If something cannot be totally ruled out, it's just a possibility.

It's certainly not 'inevitable'.