Every now and then we have a Muntjac Deer wander into our garden at night and it comes to within a few metres of our patio doors, when we put the outside light on to get a better look at it, it runs off very quickly but doesn`t head for the gap in the hedge straight away from where it gets in, it runs back and forth across the garden then eventually shoots through the gap.
We get foxes and rabbits and they head straight for the nearest exit but the muntjac seems like it has no sense of direction.
I`ve noticed the same thing when I`ve seen them on the roads
if the light doesn't illuminate the gap in the hedge then it would probably not be able to see the gap as it would be blind to anything outside of the illuminated area.
Where I live, rounding a corner in a car and seeing a roe deer on the road ahead, it'll act in the same way as your muntjac, moving nervously to and fro in front of the fence before finally jumping over. It's simply looking for a quickest and easiest way out, I'd guess.