I decided to report this as bug after several people encouraged me post it here:
I bought the Laboratory and i tried it out for the first time to make 100 star coins. After this the game froze and i couldn't hit the x-button or do anything else so i clicked all over the screen. After a while everything went back to normal except that the order had been instantly completed and i had lost 2880 gems. 2880 gems for 100 star coins??
I did write a ticket and got a reply that "accidental in-game actions such as this are not eligible for a reimbursement". Ok, right? So much for getting ANS this or next year as i've been saving for it for a long time. So here comes a few points and questions:
1) Shouldn't there be some kind of a confirmation "do you REALLY want to spend gems..." to avoid such "accidents"?
2) 2880 gems for 100 star coins? seriously? and still no way to cancel...
3) I'm using recently updated Chrome (Win10) to play the game, but i think this can happen on any browser
So my fellow settlers be extremely careful with your laboratory! I hope at least some of you may avoid loosing your gems after reading this. Personally I'm not sure I'll be using the building after this episode. It really hit my economy bad and i don't want it to happen again under any circumstances (not that i'd had that many gems any more).