A different perspective:
#1 You bought and supplied the instruments, the installer did not. Most installers will not and should not stand behind equipment they did not source or provide. There are far to many illegitimate sources out there of refurb, gray market, non-authorized dealers etc., for any installer to do so. They may choose to install it but warranty etc. is usually on the owner who supplied the product.
#2 It appears you hired a rigger not a marine electrician or electronics guy? That mast head unit install is three screws and well within the scope of the rigger. Drill, tap etc. done.. However, most riggers are not electronics guys so unless he told you up front he would do the commissioning and dealer set up, then again, that portion most likely falls on you. Did he wire the rest of the system into the vessel? Did he agree to set up and commissioning of the electronics? It also may have been working upon boot up and failed shortly there after..? TackTick stuff is VERY hit or miss.....
#3 If you had asked here in the forums, before buying TackTick, you probably would not have done so, at least if I had any input.

I will no longer install TackTick products, even if an owner supplies it. I turned two customers away last summer alone, I just don't want to get involved, been there, done that far too many times.....
#4 It seems as if you were essentially paying the installer for his labor and not his electronics expertise? Did he state that he would do the dealer set up and calibration?
We know who is at fault here, TackTick/Raymarine. We also know Raymarine will not pay ANYONE SQUAT for labor reimbursement. If the installer agreed to do the dealer set up/commissioning then perhaps he should have some responsibility but that is a very tough call unless it was in a written quote...
I had a similar situation a while ago. Owner insisted on supplying all instruments, 12k worth, and asked me to install them, which I did. (he saved $360.00 over my quote on approx 12k worth of product or about 3%) I also let him know in writing, on the quote, that I was
physical installation only and warranty was on him. He also lost extended factory support by not using me as a factory trained installer.
I spent considerable time designing the system and gave him an itemized list of all components needed, every single manufacturers part number. He spent nearly $100.00 in shipping returned items because he still ordered incorrect parts, cables etc.. (he's a die hard eBay guy) He also paid me for two hours of my time to drive an hour each way only to find out he'd ordered the wrong equipment, not the parts I specifically told him he needed.. His $360.00 in savings was nearly gone already.
When it came time to install the new radar he did not want to pay the extra yard fee for me to go to where his mast was stored and do the physical work. (yard tacks an extra 10% onto my labor as an outside contractor) In order to save $6.50 per hour, he had the yards
riggers install the radome and run the wires down the spar. It was SLOPPY work that resulted in MAJOR expenses.
Long and short was he had to pay me an additional 4 hours for trouble shooting, pinning out every single cable in the system, swapping plotters to test for a dead network bus, only to find out that the radar cable was bad which then necessitated dropping the spar AGAIN.. Long story short was he would have paid about $1400.00 less if I had just done the whole job and he would have had additional warranty time. Instead, he paid me substantially more than the original quote plus had a huge yard bill for the second mast step re-step....
The key take away is that sometimes the money you save by
sourcing the equipment yourself comes back in a bad way. This is most often true with electronics.
I have had my share of electronics fail that I
sourced and installed and I have stood behind them, sometimes at considerable expense. I have had nightmare installs where I have lost four figures because a manufacturers product is so bad. But if I sourced it, sold it and installed it I stand behind it, part of the business.. This is why there are some products I now will no longer install, due to reliability.