I finished Wall-nut Bowling 2 without losing any lawnmowers. I even have an image proving it. 
Bowling No Lawnmowers Lost

(Note that "La Bolera 2" is the Spanish name for Wall-nut Bowling 2.

It's probably nothing special, though this is the first time I completed the second one without losing a single lawnmower since the cluster always managed to get at least one for me. Post your comments in the comment section(where else?)