Soft-dome tweeter damage - NBD or permanently compromised?

Putting aside the fact you are fully justified in being upset over your new (to you) speakers being "violated", I think you're going to be okay.

IF the soft domes snapped back into their original shape (as in PERFECT!) and there is no material added or subtracted to the surface via the tape, you should have healthy, functioning, sonically competent tweeters. The good news is that the deformation was restored rapidly, not allowing the soft dome to "remember" the shape of the blemishes. "Exercising" the tweeters should relieve them of any minor misshapen issues.  Even the one's you can't see.

I can only speak of my experiences with damaged drivers over a long period of time.  The buyer/seller dynamics can get complicated. Best of luck with this.

@thecarpathian 

I believe it's a mental disorder that prevents people from keeping their hands off that which doesn't belong to them?  To make it worse, when I had initially left the room,the grill was on the speaker. 😳

I worked as a salesman at two different stereo stores: One store from 1987-1991, and the second store from 2000-2008. Both stores carried several “high end” brands. Even though, as others have said, you are justified in expecting to receive your used speakers in the condition they were advertised in (or better!), I have also contacted different manufacturers of speakers using soft dome tweeters about them being pushed in, and subsequently popped back out. (Customers would call to say their guests, and sometimes their children, couldn’t resist pushing in the tweeters). Every time I called, offering to purchase new tweeters, I was told that if they were returned to their original position, they would play as before. This did NOT apply to metal dome tweeters! My only personal experience with this was once I forgot to replace the grills on my Von Scweikert VR4jr, and one of my grandkids pushed in a tweeter. I called VSA, and they told me to just pull it back out gently and enjoy. Just my experience. 

If they are doped soft-domes (the doping essentially makes them a composite), they will typically have dimples or creases after they are pulled back into dome shape. I once encountered this issue with a pair of Dynaudio speakers that I bought as demos from an authorized dealer. Both tweeters arrived with dimples so I knew they had been abused at some point. I contacted Dynaudio directly and they offered to send replacements for no cost. They told me that in theory, the dimples would have a negative effect on performance but, IIRC, they also said it’s likely not audible. 

It is weird that both were pushed in, with no other noticeable damage. 

Soft done tweeters are in fact soft, the dome is not hard like TI tweeters. If there are no creases in the domes, they should be fine. If they were hard dome, with creases, then yes, replace. 

Since they are new to you, and this would also upset me, ask for either new tweeters, or refund the cost of new tweeters. But honestly doubt you will hear any difference between the old/new ones.