What causes the transmission to fail on a 2001Saab 9-5 SE with 66000 miles?

[Barbara T]

This Saab has had all its recommended servicing at the Saab dealership where it was purchased, An independent agent said the transmission fluid was the color of varnish due to negligence. It's been seen every 5000 miles and was a certified pre-owned car with 24000 miles when purchased in 2004. The dealership claims that the transmission fluid could change very quickly and cause problems but it's only recommended to be changed every 30000 miles. It was in for those tuneups and/but the transmission fluid change is not itemized on my receipt. The dealership is now offering to go 50-50 on the repair costs - but something seems very odd to me here. Is something amiss or is this usual? Thanks.