[Gameplay] Actions only checking conditions on the first cast and not on the end animation

If the conditions for a spell to work are lost mid cast the spell will still occur, this is inconsistent though as lost of vision will often stop a spell from casting, some also just work properly, for example you can flash away from an Alistar headbutt without being pushed or taking damage, in comparaison you can not flash away from an Udyr who's started his AA in bear form and he will stun you through your flash (works like that for pretty much all types of AA). Singed/Voli flips used to have this issue with flash as some can remember, but they got a fix that specifically targeted them. Anyway here's some very short videos example to make things more clear.

https://www.youtube.com/watch?v=eJb7ALw3WY0&feature=youtu.be https://www.youtube.com/watch?v=yowHJTRRO60&feature=youtu.be https://www.youtube.com/watch?v=OFlkUXN89oQ&feature=youtu.be https://www.youtube.com/watch?v=ZEGbgn3WW9Y&feature=youtu.be https://www.youtube.com/watch?v=GTYIDAPsvUA&feature=youtu.be https://www.youtube.com/watch?v=pQj-qTzDGmo&feature=youtu.be https://www.youtube.com/watch?v=KFUnsM77khk https://www.youtube.com/watch?v=nzowyOYzPNs&feature=youtu.be

For example in the one where Lissandra manages to use her E displacement even though she's CCed is because it has a very short cast time (but there's still one) and if she uses it right before the CC she'll still be able to cast it mid CC even though she shouldn't.

There's also the one where Katarina uses zhonya a bit before Lissandra ult is done casting so her ult ends up wasting had the game made a second condition check at the end of the cast it would have realized that the targeted unit was now untargetable and it would have simply not cast. This example is not to be confused with the bug where you can use abilities when crowd control spells overlap (which they are fixing on the pbe http://boards.pbe.leagueoflegends.com/en/c/general-pbe-feedback/R2Ue24YA-crowd-control-fix-bug-thread) had it been that Katarina zhonya would have cast while Lissandra ult was active.

PS: If it was to be fixed there should be a condition where the spell/AA can still be used mid animation up to 300 range from its max range (that way you couldn't constantly just walk out of a spell mid animation).