Conditional Sequence Flow : Condition on conditional sequence flow is evalated before the end listener on activity

During my process design and testing, I have observed that the condition on Conditional sequence flow is evaluated before the end listener defined on the service task.

In my case I am populating the isReview variable in end listener on service task after making web service call.
And on outgoing conditional flow I check for isReview condition.
But I get the below exception in execution.

Exception : Unknown property used in expression: ${!isReview}. Cause: Cannot resolve identifier 'isReview’

Is this expected behavior?

Thanks & Best Regards,
Ritesh Patel