A local window person with lot of years of experience did it. Can it be
(mis)installed when you have to just put the pane in the frame and glue
it? He changed the pane about 5 months ago getting it from manucaturer
as my earlier pane was fogged due to broken seal.

Is change in temp (as Fall is here) can be reason for break? When
maufacturer gives 5 yrs of warranty, I think I am unlucky here to
change it in 5 months. Or bad glass company also is a matter of concern
here.