I'm guessing that the problem where the attack button causes the dragons to perform some kind of spell, instead of just attack, is caused by a bug mentioned in another post where the spellbook button became mapped to the crushing blow attack, a bug which will be fixed in the next update. However, I say this partly because I'm not able to reproduce the problem you mentioned, but of course it's possible that I'm just not following the correct steps. Do you have to click on a certain unit (either one of yours or one of the enemies) in order for the dragon attack to become broken? Or do your dragons do this right off the bat? Thanks.
Raa00 - I think you're right. I just tried going back and duplicating this (fresh reload) and was unable to do it. CariElf does have Crushing Blow so it sounds like that bug could be the root cause. The dragons, with 47 attack power, were doing like 115 dmg per strike with the bug. At any rate if I see this again I'll post it. Thanks for looking into it.
[Edit] Also - I do remember the mouse icon as a magic casting icon, not the crossed swords. So gives more reason to believe it was the Crushing Blow bug. Thanks.