The real question is, why did they "break" into the non-dead bolted side door to begin with? That door can be easily opened with anything flat, a credit card for example. Zero noise. Also, that particular window leads directly in one of the two adjacent bedrooms (separated by a bathroom) in that part of the house.
Not entering through that window, but through the side door could-
a. help the defense (I/we broke in, we did not plan to wake up anyone...)
or
b. avoid the terrible feeling afterwards of a "stranger" entering through one of the ( possibly family-members') bedrooms or
c. avoid leaving "carpet - marks" / footprints in the carpet, if applicable. If that bedroom had indeed a carpet floor, I can see the prosecution smile..
or
d. make for an easier entry/ escape route
Just my opinion.
-Nin