  Magnetically frustrated spin systems compose a significant proportion of
topological quantum spin liquid candidates. Evidence for spin liquids in these
materials comes largely from the detection of fractionalised spin-1/2
quasiparticles, known as spinons. However, the one-dimensional Heisenberg
chain, which is topologically trivial, also hosts spinons. Thus, observing
spinons does not necessarily signify long-range entanglement. Here, we show
that spinons arising from one-dimensional physics leave a clear fingerprint in
magnetic Raman scattering. We achieve this by calculating the magnetic Raman
intensity of coupled Heisenberg chains. Our findings are in excellent agreement
with the magnetic Raman scattering measurements on the anisotropic triangular
antiferromagnet Ca$_3$ReO$_5$Cl$_2$.
