sounds a homework assignment question
i think the answer depends on how long after the countdown does the light turn green/red? if the light turns immediately or shortly after the countdown reaches 0 (or when the blinking hand becomes solid), i would say this is less of a hazard and more of a safety feature, as people who are familiar with the timing know that they shouldn't be crossing.
but if the countdown hits 0 or the blinking hand becomes solid and the light doesn't change for a lengthy period of time, I would say this is a hazard since pedestrians would try to guess whether they have enough time to run across. drivers making turns will see the countdown is over or a solid hand, and may not expect a last second runner try to bolt across the crosswalk.