MBenz Aussie

Hi All.

A friend of mine dropped by the other day and asked me for some help with his convertible roof. I have a 2008 clk convertible.
He had taken his car in to a trimmer to have the canvas roof replaced with a new one that he had bought.
The trimmer phoned him later in the day to say he couldn't open the roof. and yet my friend had used it just a day or so before.
So he went and picked the car up, he noticed there was no oil in the roof reservoir, so went and bought a bottle of oil from the Mercedes Benz dealer and topped it up.
Then he tried to open the roof.. no go. he noticed the oil had dropped again in the reservoir. So he came around to ask me for help. We looked for leaks around the Hydraulic pump and the rams.

We couldn't see anything obvious.. the next day he took the back seats bases out and found oil on the floor underneath.
He came around again and we had a very close look at everything and we found this...this is after we took the top part out doing the replacement. We haven't got to the base yet.
He got a price from the Mercedes Benz dealer for ONE new main lift cylinder...AU$2,500. needles to say he bought a second hand one.

I know its a long story..but can anyone hazard a guess as to why or how this happened to the Main Lift Cylinder..because it has us stumped.
We thought maybe the trimmer drove into a garage roller door while the roof was half open and jammed it so hard it pushed or pulled the cylinder.. buts its only one ( So Far, we haven't got to the other one yet )
No wonder he was losing oil...
What could have caused this, any ideas anyone ?
Any comments appreciated

MBenz Aussie