Glass is tricky...and then it gets a bit tricky. And right after that...it's tricky.
@Lourdes Acevedo The issues is the backing of the tile chosen (whomsoever choses the tile...choses the issues that come with it).
The question you asked is, does this whole job have to be redone. Sigh. That's an answer only your GC can answer. Why? Because it is THEIR skill set and their JUDGEMENT that made him/her say "Good enough. No will notice! Yah. I can get away with that! I'll just take my money an walk away."
You have to be confident in this person's JUDGEMENT and INTERNAL DIALOGUE that s/he will be GOOD ENOUGH to change this out without damaging anything else.
If this has been grouted (I see grout...but I could be wrong) then you will lose the tile to damage (the one's s/he attempts to remove). Which means you must have MORE left over.
The other question becomes, can s/he do a BETTER job (please look up a few paragraphs...someone's internal voice said this is OK) than what happened in the past.
A great man once said, "The Definition of Insanity is doing the same thing over and over again while expecting different results."
A GC is not a tile setter....for the most part. I know several tile setters who trained under German Meister Masons (who did all the Draughtsman courses in Germany) who turned into GREAT GCs. But most tile setters stick to their expertise. They get all the income they want just by doing a great job.
So ask yourself:
1. Is my GC a TILE setter or did my GC HIRE a tile setter? - Get them to answer that one.
2. Is the tile SOOOO bad that even a PRO with glass tiles (I know one person...he specializes in glass from HD, Lowe's, Rona, etc) is going to have a hard time???
3. Why is the cut edge being used against tile? Why isn't it being hidden by trim/caulking in the last row?
4. And why wasn't a white thinset used behind white backed glass tiles???
Q