Doing some BS problem solving and came across this beauty: $$S \cdot \text{exp}\Big(-D(T-t)\Big) \text{exp}\bigg(-\frac{d_{1}^{2}}{2}\bigg) = E \cdot \text{exp}\Big(-r(T-t)\Big) \text{exp}\bigg(-\frac{d_{2}^{2}}{2}\bigg)$$
$d_{2} = d_{1} - \sigma \sqrt{T-t}$ so it does not explain the difference.
