In order to give every alleged offender an opportunity to give their explanation and to be able decide whether there are grounds not to continue to prosecution.
It is clear that the OP knowingly committed the offence and has admitted so. Every case is treated on merit, we only have the benefit of the OP's explanation on here, it may be that the inspector's report contains clear evidence that indicates prosecution should continue.
They should not have, but we all know that sometimes accidents do happen. ( the offence with which the OP is charged is not an accident.) U