This is a very good question. Below are rule and case book references to answer this question.
Rule 5, Section 10 states: An escape is when the defensive wrestler gains a neutral position and the opponent has lost control while the supporting points of either wrestler are in bounds.
Rule 5, Section 20, Art. 3 states: A neutral position is one in which neither wrestler has control.
As you can see from the rules references above it basically comes down to judgement. A neutral position is when neither wrestler has control and an escape is when the defensive wrestler gains that neutral position when his opponent has lost his control. The case book is great resource for this question as it breaks down this position.
Situations:
From the starting position on the mat, wrestler B quickly stands up and strips the hands of wrestler A and turns and faces. This would be an escape.
If wrestler B starts towards the edge of the mat, strips his the hands of wrestler A and is more than an arms length away with the back towards A just as B goes off the mat it may be possible to gain an escape in this situation provided A does not follow up and try to maintain the advantage. The key here is that wrestler B has not turned and faced wrestler A. But if wrestler A is content to let wrestler B go without trying to maintain advantage, it should be an escape. Again, this is in the judgement of the official.
If they are going out of bounds, across the boundary line, in this same situation it would not be an escape as the loss of control isn't until they were out of bounds.
When the defensive wrestler is able to stand, turn and face the opponent and break the locked hands and separate them to the point that they both cross the midline of the back, control is lost and an escape is awarded.
As a wrestling official you have a very tough job as the majority of the calls made are judgement. Getting an abundance of mat time and studying the rule and case books will help you in making the correct calls. Wrestling is a sport where the obvious call may not be made by the naked eye but by feeling that situation. Control is felt not always seen.
