Vehicle stolen. person arrested. COSTS Q ?

So your son authorised it to be towed (by choosing it to be taken to a safe place), or did he just expect it to somehow magically be beamed to this safe place and not incur any towing or storage costs? The towie hasn't accepted your sons offer of the wreck only and has requested an extra $100 on top. Has your son checked out what the wreck is worth, asked what the towing and storage costs are? Guess this is a lesson for your son to get insurance next time. He can submit costs to the Police to seek reparation, which is often awarded from my experience - the problem is however is getting the money out of the crim (the saying 'like getting blood out of a stone is pretty apt in this instance).

my sons paid the towing chap all monies owning as he realizes he has a business to manage

His aim now is to get reparation form this thieving perpetrator

A few years ago my daughter"s Honda 50 was stolen from our back yard late one night. The police were called to two youths riding it in a city park that night. The police recorded the driver as my daughter from the rego. We reported the Honda stolen and the bike turned up in the back of a stolen Legacy wagon which had been recovered. The wagon (and bike) were towed to the tow company's yard and I got a call from them asking me to come and collect the bike. I forget how much the tow company manager wanted for the tow, but we settled for a lot less ($60) and I took the bike home. My daughter was living in England at the time and I didn't fancy having to explain where the bike was when she finally returned.
I did make some effort to get the police to identify the youths riding the bike in the park, who I suppose also stole the Legacy, but the officers involved were on leave for weeks so we never got any answers.
I found having to pay $60 to reclaim our stolen bike bemusing, but the alternative was to abandon it.
The fact that people caught riding a motorbike (stolen or not), in the middle of the night, in a city park, weren't positively identified was also a big surprise.

I have to ask, if the truck is worth $10k why the hell didn't he insure it? Do you think a criminal who doesn't care about the truck is going to pay?

That was my question as well. Even my little old Laser that I paid $1000 for I insured for fire, theft and third part for $1500 (it had mag wheels lol). And when someone went through a stop sign and wrote it off I was every grateful if for that money, when the insurance company paid out.

did he own money for drugs

If you get to the point of a court ordered reparation, a word of advise, stay on their case to ensure it actually happens. if it get all to hard the court, in my experience, tend to just let it slide. in my case i had an order awarded for $600, but after a couple of months the court said, oh a mistake was made so we have decided to not pursue payment. Oh yes i said can i sue the person for the money instead. then the whole thing was back on track and 1 payment was received, then stop. then the court said the person had died, so it was all over. oh yes i said who is looking after his estate. to put a long story short his mum has her benefit docked $25 per week to pay it back!