  The optical lightcurve of GRB010222 exhibited one of the slowest decays of
any gamma-ray burst to date. Its broadband properties have been difficult to
explain with conventional afterglow models, as they either require the power
law index of the underlying electron energy distribution to be low, $p<2$, or
that the outflow is quasi-spherical thus reviving the energy problem. We argue
that the slow decay of GRB 010222 and a linear polarization of $1.36\pm 0.64$%,
is naturally explained by a jet model with continuous energy injection. The
electron energy distribution then has $p=2.49\pm0.05$, fully consistent with
the expectation from detailed modelling of acceleration in relativistic shocks,
that $p>2$, thus alleviating the ``$p$-problem''.
