DEF in my diesel? How did this happen?

My truck stopped running yesterday after running rough. It happened pretty fast.

Mechanics state that there was a lot of DEF fluid in the diesel and that the only way for it to get there was to be pumped into the tank. The truck is a 2013 Freightliner. Since I didn't pump the DEF into the diesel tank, is there another way for this to occur? Was I sabotaged? Was it all just some black magic?

Please inform me...

 

No, I'm a company driver. I've been putting in DEF and using it for years. It's not an easy mistake to make so I'm 100% sure I didn't make the mistake. I mean just look at the openings for the DEF and for the diesel. Not only are they a completely different size, different caps, etc. but they aren't even located next to each other. The investigation isn't complete yet as the truck was just towed last night from my company over to a repair shop to be looked into further. But I am being told that the issue with my truck running poorly was too much DEF in the diesel. This has me completely perplexed at the moment.

 

Yes. But days? My shops mechanics told me the last time this happened the truck was out for months and that they charged the driver something like $23,000.

My truck was running kind of rough a couple of days prior. I've had issues with this truck in the past with rough driving and a check engine light that is never fully addressed by my mechanics. The previous driver whom drove this truck had the same issues. I was told, when I get the check engine light, to just keep resetting the power switch (that little switch on the Freightliners near the driver's seat that shuts off all power to the truck). I was told to flip it off for about 30 seconds at a time, do it about 3 times and see if that fixed the check engine light issue. Most of the time it worked. My mechanics were aware of this issue with my truck.

A few days ago when my truck was running rough it felt like it needed a regen even though I didn't get a regen light on the dash. I pulled over, tried a manual regen and the truck didn't regen. I shut if off and let the truck sit for a few minutes. When I started it back up it ran fine. I marked it up as just another quirk with this truck. It has a few including those I listed already plus my Jake break magically turns on when it wants to. It's a fun truck.

 

No the tanks aren't locked at all. My truck was parked with me in it at the terminal prior to this happening. The lot isn't secured but it doesn't seem likely that someone sabotaged the truck. It could happen, just doesn't seem likely. Overall it doesn't seem like my company has many disgruntled drivers. I am the only one that drives this truck too. No slip seating.

 

This whole thing concerns me though. For one, they say they don't have a replacement truck for me to drive currently as they are giving the available trucks to those coming out of orientation. Second they said they won't pay me breakdown pay (which really isn't anything anyway) until the "investigation" is complete.