[confir]Gaea's Herald-Sawtooth Loon and such bad interaction

[Aswan jaguar]

Describe the Bug:
AI had only Gaea's Herald and cast Sawtooth Loon it draw 2 cards and put 2 on library but didn't return to hand Sawtooth Loon with it's other ability.I tried just now myself and yes if you select firstly Sawtooth Loon etb trigger and then Gaea's Herald trigger (uncounterable sign to Sawtooth Loon) then you don't have to return it back to hand.If you select first Gaea's Herald trigger then all is good.

Which card did behave improperly ?
Gaea's Herald most probably (it's effect lasts too much and so affects etb triggers)?

Which update are you using?(date,name)Which type(Duel,Gauntlet,Sealed Deck)
Manalink 2016/08/27: Eldritch Moon v2, duel

What exactly should be the correct behavior/interaction ?
Gaea's Herald stops counterspells and counter abilities to creatures being cast and not interfere with etb abilities or something like that while Sawtooth Loon has etb abilities that should always trigger later.

Are any other cards possibly affected by this bug ?
-

[BAgate]

Don't know if related, but when AI cast Sparkcaster with a Gaea's Herald in play it entered the bf with an untargetable symbol on it that never went away.