P0705 error after having work done

2 weeks ago I had the unfortunate Monday morning of having someone swipe my tail light with their mirror in traffic. No huge deal, her insurance paid to have it replaced and I got some Cadillac SRX rental car to play with for two days.

I picked up my truck on Friday, they were even so nice as to wash it(for some reason, which actually made me a little suspicious, especially considering they called and said the truck was done the day before, but for some reason were only washing it right when I came to pick it up....). Everything seemed ok but halfway home on my 10-15 minute drive I noticed my check engine light was on. This was the end of the day on Friday half hour before the shop closed, didn't have to drive anywhere all weekend, back to work today, I start the truck, check engine light is still on, but now I notice all kinds of weird tail light issues with the one they replaced. Some of the wires must be touching each other. Regardless, I called the shop, they said to bring it by and they'd see what's going on. I didn't bring up the engine light yet because I had no idea what it was or if it was even related.

Stopped at autozone on my way home and got a P0705 error:
Transmission range sensor circuit malfunction/open or short circuit condition/poor electrical connection/misadjusted tr sensor/Failed TR sensor.

Didn't really sound like it was related, but the more I read online about P0705 errors ( http://www.tacomaworld.com/forum/technical-chat/86096-p0705-park-neutral-switch-2.html ) the more I wonder if the likely short in my tail light wiring is doing something to cause a short in the Trans range sensor circuit. I've also read a ton of people on here talking about getting water on the wires to their junction box that seems to be coming through that grommet from the engine room through into the cab of the truck. This is where I get more suspicious why they actually washed my truck, and what the chances are they got some water under there and I was driving home the water seeped all the way to the junction box causing a short and turning on the check engine light. It'd be nice to think that the shop was just so thorough that they wanted to clean my truck, but they didn't even finish cleaning the scuff off of the side of my truck until I pointed it out to the guy and he said "oooh, that should just come off with some compound.... do you want me to go get some??" YES, that's why you had my truck for 2 days!!

Anyway, my truck is going back when I get some time, but I was just looking to collect some opinions/information on whether or not you guys think the two might be related so I can push them to look into it and fix them, or if it just seems like a coincidence that the light kicked on during my drive home, and I should just try to clean those connectors and seal off those wires better myself and hope it solves my problem like it has for some of the other guys. I know the two sound like they could be potentially related from sitting here and reading all of this, and it makes plenty of sense, but obviously the guy at the shop isn't going to be interested in sitting down to ready TW.com posts for half an hour and take the opinions of a bunch of guys he doesn't know, so chances are if I bring it up with my limited knowledge on the subject they'll just think I'm nuts for blaming a transmission sensor problem on the tail light work they did... thoughts??