>My code would not fail because it IS IN the Valid() method of the grid column's textbox, since we are IN the grid, then, we are IN the grid's cursor area. Let's remember that whenever we are IN a grid the cursor bound to the grid is SELECTed.

Hm, how can be sure?
What about:

IF thisform.SomeMethod() && Here you change current alias and forget to bring it back
   *** Your Code here
ENDIF

And BTW this code shows habits. If you program that way here you will do the same somewhere in the application where you can not be sure that you are int the right alias.