bad window job

i just had a broken window replaced on my ford winstar, driver side sliding door,

then i watched the mechanic try to fit the new window in the frame, he tried to drill holes where the screws were supposed to fit into the frame, then after having a hard time with fitting, he finally just clipped the screws off the window with clipping plyers, about 12 screws, and glued the glass onto the frame with glue, a type of black rubbery glue that takes a few days to completely dry,

i got a real good deal on the window, i guess it is not the exact, proper kind for a ford winstar,

was this window job good? should i get the right glass with the screws that go right into the window frame,