IT IS POSSIBLE TO GET LS + LDoA legally...
Was anyway... These are the possible (Legal) ways one could have obtained both (Don't quote me on the data of fix please, I'm just giving the datum if which I THINK it was fixed):
1) (Confirmed by me)
In the early days, one would rez automaticly at the shrine, if the other team member used/didn't have a rez signet... (Even if he was alive), so one would be able to deathlevel someone else. However, I'm not sure if anyone did it, seeing there was NO point in doing it back than. (Neither LDoA or LS excisted)
This means that if someone was aware that both titles were going to come in a future update, he could ask a friend to level him to lvl 19, 99%, and then when both titles are introduced, accept 1 quest reward to get LS+LDoA...
This got fixed about one month after GW.
2) (Unconfirmed by me, but I think it's listen in Wiki Talk somewhere + I know some people who confirmed it themselves)
Untill a few weeks after GW release (The real one), one would get 10 experience every time he completed the "Farmed Dirk and his retarded Price-Hogs"-quest... This quest took about 5 minutes, in which you would have to get 4-5 hogs in a small area. On completion, one would get a "hidden" 10 experience (Only saw the experience go up, but no actual "emote" (The one you get after raising exp)) and 10 gold.
This got fixed about one month after GW. (There is a player-guide somewhere, player-written, which CLREALY states the 10 exp reward. Obviously, this wasn't a big deal seeing noone really understand the "power" of repeatable quests back then.)
3) (Confirmed by me)
There was a glitch in the "Rites of Rememberance" quest. The "reward" for this quest worked differently than every other quest in the game. One would actually recieve the experience RIGHT BEFORE THE ACTUAL "REWARD". As in, if you were able to somehow "postpone" the conditions to accept the reward, you would still be able to get experience. Now this problem was easily solved by talking to her when having a full inventory. One could click the accept button, get the experience, followed by the message "You currently don't have enough room to accept the item, bla bla bla". Than, simply rezone, abandon quest, and redo it

I have NO clue when this got fixed, but I think this wasn't too long ago...
So IF you ever find someone with both titles, don't call him a "glitcher". Sure, these ways arent "fully" legal, but than again, there is enough people that "abused" shadowstepping pre-nerf, Grenth's Balance, etc...