This is probably something you should have asked Bayer when you contacted them; it is also something that should have been asked BEFORE the product was applied. We tried searching the Internet on the product and all we got were advertisements for it, which would hardly have mentioned ill effects of the product.
We went through one of these advertisements, clicking on the link for Product Details, which gave us a video on application. The main message we got from that was that you should carefully read and follow the instructions on the label. Since this is a systemic, which means it travels up from the roots into all parts of the tree, and is a poison, we would certainly agree to the advice not to eat the pecans for this year. Beyond that, we have no way of knowing when it will again be safe to ingest those pecans.