That seems like a very real effect, but the votes need to be disclosed after they occur. Otherwise, the lobbyists have even more power, because the committee has an incentive to collude with the lobbyists, if their individual votes are not known, and they accept bribes. (I agree that having their votes be unknown helps if they do not accept bribes).
The only foolproof solution is to remove power from the lobbyists.
The only foolproof solution is to remove power from the lobbyists.