I'm not a professional tiler but I reckon I could do better. In the first picture but the gap between tiles looks uneven (not square). In the second picture the gap behind the tiles looks slightly large suggesting the adhesive was a bit thick and they don't look flat/level.

Gaps/grout lines between tiles can be made uniform by using tile spacers (or even match sticks).

Tiles can be levelled using a serrated adhesive spreader and a tile beater block to press them level with surrounding tiles. Once you've been shown how to use one of these blocks it's easy to get tiles very flat/level.

http://www.rubi.com/en/tile-beating-block-r326

Personally I prefer to fit tiles using spacers then when the adhesive has set (eg next day), remove the spacers and do the grouting. Did your man try and do the lot in one go?