That the Sen could be using his elected position to influence approval. The Ethics rules require even the avoidance of an appearance of impropriety, and this fails that test. The question is obvious. I didn't say he actually was being lobbied, only that it raises questions. It does, legitimate ones. Public servants need to forfeit certain things, this is one of them.
News flash: Lobbyists exist for precisely this purpose, to influence members of Congress and the Senate to gain favor for the company the lobbyist works-for. A certain well known Senator, who was on the Defense Budget Appropriations Committee, also held quite a bit of stock with Raytheon. Was there influence that personally benefited the Senator? None that was ever investigated. Tis the way of the world.