The thing with LA is it is subtle. Then without them saying in a special feature about how their milestones reveal something about Callen's past it would be easy to miss. But then even NCIS hasn't always done something special, it is more the later ones. Either way what was said in this year's special features I think were wrong. Both shows have done special things for milestones, just in their own ways. Although now I can't see what I'm remembering they have said about their milestones but I didn't get much sleep which doesn't help
It'd be nice if LA did do something special & make a change & focus on more. We've done quite a bit of Callen reveal, time to move on to more things
Ep 100 - 5x04 "Reznikov, N." (While investigating a kidnapping case of a man who claims to be Callen's father, the team soon find themselves in grave danger.)
Ep 200 - 9x08 "This Is What We Do" (When a group of migrants and Border Patrol officers are slaughtered near Camp Pendleton, the team discovers that the killers are there for one of their old enemies; Nell must work with her bossy older sister Sydney, a Homeland Security analyst.)
Then 250 was "Mother" so I think that was at least special... 50 & 150 didn't sound like much of anything...
Meanwhile NCIS:
Ep 50 - 3x04 "Silver War"
Ep 100 - 5x06 "Chimera"
Ep 150 - 7x12 "Flesh and Blood"
Ep 200 - 9x14 "Life Before His Eyes"
Ep 250 - 11x16 "Dressed to Kill"
Ep 300 - 13x18 "Scope"
Ep 350 - 15x10 "Sight Unseen"
Ep 400 - 18x02 "Everything Starts Somewhere"
Looking at that list I think 200 & 400 are the only special ones for it too