AD Lux?

Alright, this is from a game I had today, which I thought was a bit strange. We had a Lux who decided to go with an AD build, which confused me a bit but I didn't speak up about it since we were winning anyway. But the build didn't seem very viable from my perspective since I don't really see the benefit in it as oppose to a AP build with her. 

I understand that some casters, like Janna, are viable as an AD build, but I didn't think she was. Janna for instance has her slows and knock ups, which she can benefit more damage wise as an AD build. I know, I've been rolled by AD Janna a few times. Though she tends to fall apart a bit more towards the end game. Other characters like Kennen are sort of viable with an AD build, but I still prefer the AP on champs like him.  There is also the reverse roll on characters playing AP on an AD champ. Some good examples being characters like Shaco and Yi (AP Yi blows). In some cases these work well (cept for AP Yi), but that really depends on who is playing the champ (cept Yi). 

As for how did he do? Well, if you have LoLReplay, you can see that here. But the tl;dw version is that it wasn't that great. Her damage output was low with her spells and with the AD stuff she didn't really bring much to the fight, and ended up with a negative score. I believe his odd choice of build was why the progression on bot lane was rather slow and noneffective. But who knows, maybe someone has pulled off an AD build with her and it is viable in some way I don't see. I just thought it was an odd happening and was worth noting, and I am quite curious to what you guys think. Can AD Lux be pulled off? Or is it just a horrid thing to even attempt?