I wonder if he typed the response himself or foot tapped it to a secretary in Morse code?
It all depends on whether the secretary was gay or straight. LOL
When I worked for a Congressman many years ago as his issues secretary, he would sometimes dictate a statement, hand write it or give me generalized instructions as to what should be said and then approve my draft with any changes he wanted inserted. If the process still works that way, then LEC/ben would mean that Craig wrote or approved the letter, and it was typed by ben.
As to what might be lost if he resigned now, I would like more information. What are his seniority valuable assignments [almost wrote positions, but thought better of it]? What are his committees and subcommittees, and what specific bills has he introduced or is sheparding through the legislative process? It is a reasonably good excuse, but inquiring minds want to know if it is just a smoke screen.