Odd Fuel release during a compression test??

[dog3leggeddog]

Hello All,
I am new to the forum and have a question about what possibly may have gone wrong during a compression test. My car is a 1981 240D automatic W123. I previously owned the car and recently purchased it back from the individual that I sold it to. The car was running, starting fine when I sold the car a few months ago. It was a little cranky on cold mornings, but would start. I notice the car on craigslist again a few months later stating that it needed a new engine. Long story short, I bought the car back to part out and keep a few things. Just out of curiosity I thought I would see why it would not start. Checked valve adjustments and cam timing all OK. Pulled the injectors to do a compression test with less than happy numbers. #1-300,#2-150, #3-200, #4-255. The weird thing is when I did the last cylinder the engine started gushing diesel out of the injector hole #1. I'm not sure if I did something wrong here. I put plastic caps over the injection pump fittings and held the stop lever to halt fuel to the pump. My guess is that fuel pressure was building up in the pump and dumped fuel into the engine from the back side of the pump. SO, is this possible and do you think my compression numbers are even accurate? I would not think the engine would have ever ran with numbers that low and I was driving it months ago. Any thoughts are greatly appreciated.
Regards.