It looks like they got contaminated cinnamon. Lead (II,IV) oxide (red lead) is a reddish-brown pigment which could have been used to adulterate the cinnamon to

It looks like they got contaminated cinnamon. Lead (II,IV) oxide (red lead) is a reddish-brown pigment which could have been used to adulterate the cinnamon to make it look better (hide imperfections since it's close to the color of high-quality cinnamon bark). Similar to how lead (II) chromate gets added to turmeric to hide imperfections. So I'd not rule out deliberate addition of red lead to allow selling a cheaper product.