Obviously there are latches built into the armor for situations like this, but Tony's own need to get out of the armor combined with Loki's anxiety has the god tearing armor pieces off in a frenzy.

The faceplate is first. Loki rips it off and tosses it to the side as he begins working on the gauntlets. The god babbles as he goes, swinging wildly between concern for his bonded, and anger at the ones who did this.

"They're dead. Does anything hurt? Whoever did this, I'm going to kill them. The shrapnel, is it-? I'll hunt them down like beasts-"