  ZrSiS has been identified as a topological material made from non-toxic and
earth-abundant elements. Together with its extremely large and uniquely
angle-dependent magnetoresistance this makes it an interesting material for
applications. We study the origin of the so-called butterfly magnetoresistance
by performing magnetotransport measurements on four different devices made from
exfoliated crystalline flakes. We identify near-perfect electron-hole
compensation, tuned by the Zeeman effect, as the source of the butterfly
magnetoresistance. Furthermore, the observed Shubnikov-de Haas oscillations are
carefully analyzed using the Lifshitz-Kosevich equation to determine their
Berry phase and thus their topological properties. Although the link between
the butterfly magnetoresistance and the Berry phase remains uncertain, the
topological nature of ZrSiS is confirmed.
