Yes, they are different situations.
Does the fact that Highland Park involved a guy in a sniper position on a roof, negate the fact that a good guy with a gun stopped a slaughter in that mall in Indiana?
Why is Dick Durbin even eliciting such testimony from her, to get her to say that a good guy with a gun would not have been able to stop the Highland Park massacre? We will never know for sure, but even if true, what does that have to do with the concept, that a good man on scene can stop a madman bent on destruction?
No, it just proves that Democrats will whine about anything in their crusade against self defense.