Until such time as an accident investigation report is published, the possibility that this was a simple case of crossing misuse gone wrong must remain on the table. Given the extent to which abuse has been found to be a causal factor in past incidents, I see no reason to be getting so hung up on the precise wording of crossing instructions at locations other than Kisbeys UWC. Once we know that this was a problem then we can think about what needs to be done about it.
But I stand by my point. Clarity of instructions notwithstanding, familiarity with crossings aside, the train was clearly visible to the tractor driver. No signaller would have given permission to cross at that time, so the tractor driver acted on his/her own judgment.
I would also like to amplify what
@Bald Rick said about UWCs up-thread.
Given the proximity of the crossing to the farm buildings, it shouldn’t have taken the farmer, who will be very aware of how the crossing works, more than a couple of minutes to brief any new staff on how to use it in the event that they are unfamiliar. Given that they are risking his/her machinery, it would seem to me to be an important safeguard.