Understanding why one dog barks in the early hours of the morning.

I live in an area where there are many dog owners – and I have a pet dog, and many dog owners in my community own more than one dog and yet of all the dogs within the local community there is only one dog who continuously bark throughout the day and night and on a regular basis this particular dog even barks well into the early hours of the morning.
The persistent barking of the neighbor’s dog is not really surprising to the vast majority of dog owners who live in our local community as an example being the barking dog owner regularly arrives home in the early hours of the morning, usually on the weekend, and is definitely incoherent from the adverse effects of alcohol abuse – the only evening he will not go socializing is on a Monday evening, so six days of the week he will arrive home in a drunken stupor.
A regular occurrence being on the weekend the drunken neighbor arrives home at usually around 0130 hours and eventually enter his back garden, where is his dog permanently resides – no bedding or sheltering facilities are available, and play games with his dog for at least thirty minutes, the game usually comprise of tug-of-war with a soft squeaky toy – yes this occurs at 0130 hours in the early morning, occasionally the dog releases the squeaky toy and the drunken neighbor falls spread-eagled on the ground – a few weeks ago the dog released his hold on the squeaky toy and the drunken neighbor fell down the back gardens eight steps and fell asleep in that position until about 0600 hours – I decided not to interfere with the game between the neighbor and his dog and resisted the temptation to call the emergency services – previous calls to the emergency services resulted in the neighbour verbally abusing the good Samaritans – so the onlookers no longer participate in this neighbor’s games.
Unfortunately when the early hour games finally concludes, silence is never the end result as the neighbor’s dog is by this time very excited and this excitement continues for at least another hour with the dog barking, whining and howling, so in reality the early morning entertainment between the noisy neighbor and his noisy dog in the very early hours of the weekend, means that sleep is in short supply in my community and returning to work the next day means a lot of stories to tell colleagues – unfortunately my colleagues accuse me of story-telling.