Temis the Vorta wrote:
My take is this: since Moll had a "magic" top that would tell her whether she was in a dream, her assessment of whether she was in a dream or not must have been accurate (assuming the movie is playing fair with the "rule" about the top) and if she thought she was still in a dream, I say she was right. At some point after she "woke up," she spun the top and it didn't stop on its own, leading to only one sensible conclusion: jump off a ledge (and frame your stupid pigheaded husband for your murder so he'll kill himself or at the very least, be executed).
That doesn't make a lot of sense. If the top still won't stop spinning, then all Mal had to do was to show it to Cobb to prove her point instead of framing him for her murder. The more likely scenario is that Mal span the top, it fell, but her paranoia led her to believe it wasn't her top (otherwise it's a big plot hole.
Also, if Mal was right and they were still dreaming, then what's stopping her from "kicking" Cobb back to reality? Or if she can't, just come back into the dream (rise from the dead, from his POV) and show him she survived?
The fact that Mal stayed dead in what Cobb perceived as the real world proved it was indeed real.
Now, did Cob return to the real world at the end? I think so: the top was wobbling and since we didn't see the kids' faces before we can't tell if they changed or not.