This will take some explaining

I live in a semi rural area in what used to be 1 of 6 tied cottages built in 1890, to the front sadly now a by-pass to the rear open fields, farmland and copses.
My garden is not attached to my property but is actually 100 feet away, the garden of my neighbour's to the right of my property comes first my follows on from his.
For us to access our gardens we have to use a track that runs adjacent to both gardens, this track is over 300ft long, it was many many many years ago the property of the council.
Our properties have had 'right of way' up this old track since 1890 ish, we are allowed to have service and trades men use it and we are allowed to use it with 'vehicles of the day'. We are not allowed to block it or park in it, which we adhere to.
We drive our cars up the track and park on our garden at the top.
This track was bought from the council some 40 plus years ago and is now owned by the gentleman in 'the big house' right at the top of the track.
We have lived here for 11 years and in all of that time he has done nothing to mauntain it, between my neighbours and myself we cut the grass and trim back the hedges as best we can so that the track is passable.
The 'foul drain' to his property runs down the track, the drain cover is kept clear by us for access, our foul drains join up to the main one in the track.
This morning 7am when I went up the track to our garden with my 6 troop of dogs all was safe and clear on the track.
At 10.30am when my OH called by from work to take them for a walk there was a dirty great big hole, the ground had collapsed and now there is a 10inch diameter hole that falls in to a gaping chasm of nearly a foot diameter, it is about 3ft from the foul drain right in the center of the track and not were vehicle wheels would pass.
We have notifioed the landowner he says he will view it tomorrow.
Question
As it's his land is it his responsibilty, or can he ask us to pay for repairs if it should be that the drain has collapsed?
No where in our deeds does it say that we are responsible for wear and tear or maintenance of the right of way on his land.
I would add his first comment when informed was 'is it where the cars drive over'!