[confirmed]Metathran Aerostat can cast crit face down

[Aswan jaguar]

Describe the Bug:
Metathran Aerostat: If there is enough mana to mana pool (and only then) to put in play a creature with morph ability with Metathran Aerostat 's ability then you can put it in play also as face down as the prompt appears and you can select to cast it like that.
Is this behaviour known to you devs? There is at least one other case for a different bug that I tested recently that happens also only if mana is in pool.

Which card did behave improperly?
Metathran Aerostat? put in play mechanism?

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?
Metathran Aerostat ability with morph creatures can't put them in play as face down no matter if mana is paid through tapping lands or from mana already in mana pool.

Are any other cards possibly affected by this bug?
Yes, if needed I can find the other report.