Of course there is always the 'luck of the dice' chance, but other than that it really makes little sense that Cyndane was able to defeat Alivia so handily.

Let's look at some of the facts.

1) Alivia was stronger than Cyndane, -maybe- even without her angreal.

2) Alivia had a fairly powerful angreal which was multiplying her strength by at least 3 times, more likely maybe 4-5 times or more. Cyndane had NO angreal.

3) Alivia had a ter'angreal to unravel any weaves directed against her directly (similar to Mat's) where she need not even spare the effort to slice it. So the possibility of Cyndane shielding her (even never mind the angreal) would be virtually impossible.

4) Alivia frightens Nynaeve with her strength, and Nynaeve has come face to face with several Forsaken.

5) Alivia is approx 400 years old, likely older than Cyndane ie Lanfear was and since the age of 12 or 13 she has been trained solely to be used as a weapon. Cyndane may know more weaves, but no reason to believe she knows more battle weaves.

6) Alivia commented that The Asha'man may be called weapons, but she was confident that she was far, far more lethal of a weapon.

7a) Nynaeve who was definitely weaker in the OP than Alivia, and definitely less experienced in the OP than Alivia has defeated a Forsaken at or above her strength and who was far, far more skilled than her both in the real world and in TAR, SO why could Alivia not do the same when she towered over Cyndane in strength and was far more skilled than Nynaeve was?

7b) Many Forsaken have been defeated by less powerful, less knowledgable and less skilled oponents.

Basically between Alivia's 388 years of using the OP as a weapon, her ter'angreal and her quite powerful angreal it should have been like Rand dealing with Damer Flinn, ie: No contest.

Alivia should have actually been able to shield Cyndane quite easily without Cyndane being able to prevent it. Besides luck, or the Pattern protecting Cyndane for some higher purpose how do you explain how Alivia came off as the 'loser' in that fight? Yes she prevented Cyndane from getting to Rand, but she did not shield, capture nor kill Cyndane which is what the odds are in her favor to do.