Certainly, from what you're describing, the situation is not good. For 'everyones' benefit, long runs of the duct just provide more 'opportunities' for problems with obstruction and venting. Plus, AVOID if possible at all costs using the flexible ducting. Lint tends to hang up in those much more 'regularly' in these ducts. AND, the fewer turns, the better for the same reasons.
At the same time, if the attic is unheated, the duct should be insulated. If not, condensation will form and you'll most likely have future problems with mold/mildew and moisture dripping down.
There is metal dryer ducting at the Home Center. And there is 'flat' ducting too if the dryer is right up against the wall. (It may need to be ordered off the WEB or out of a cataloge if the store doesn't have it.) Just last week, I caught a News Program that showed dryer lint and flexible ducting catching fire due to clogged vents. Actually, the dryer fire spread to the plastic ducting and the house was history. This is most common with ELECTRIC dryers according to the program. They didn't say anything about gas dryers.
If you have more ?'s, ask away. My best to you (and your neighbor) and hope this helps.