Hi, again.

re: "...how can I prove that the transmission was in good working condition before the flush?..."

Part of that depends on your presentation -- how you present yourself to the judge as an honest (and innocent) person, and also how you carefully and clearly present your evidence (documentation).

re: "... I have the inspection paper form Tireman were I took my car when I bought it(couple weeks before the flush). Do you think that this could be the prove that the car was in good condition?..."

It depends upon what it says. If it clearly indicates that you took it in for a general inspection -- e.g., a pre-purchase inspection -- for which you asked them to examine the entire car, and they didn't write any criticism of the transmission, that would be a strong case in your favor since they are attesting in writing that the transmission didn't show any problem worth noting. It would be assumed that this included a look at the condition of the ATF.

Another thing would be what was written on the first Midas work order. Does it read that you're doing the flush because there's some (or any) problem that you are concerned about? Or does it just read that the flush was for a routine service. If the former, it's bad for you; if the latter, it's very good for you.

And finally, it would be very good if that same first work order did not state any recommended additional work on the transmission -- in other words, they're saying that after the flush, there is no problem with the transmission. It actually works against them, because they are confirming (in agreement with you) that there was nothing additionally wrong the transmission (i.e., no further work is recommended) -- at least until the line started leaking after you left the Midas shop.

Of course, the final thing that you would want to make your case is a clear glass jar full of a sample of the dark brown fluid as it is now, together with another jar full of fresh, new transmission (as it's supposed to look after a fluid flush). This would be just a dramatic gesture, but it may sway the mind of the judge in your favor if he/she isn't "car savvy".

An analysis of the dark fluid would be ideal, but that would be expensive, I assume.

Good luck.