I havn't had a cham in a couple of years. It was also a veiled, not a panther, but I that experience can be translated to panthers...
I used a combination of fake and real plants. I plan to use the same this time around. I have not had any problems, but I suppose it is a possibility of the cham accidentally ingesting some of the plastic leaves. I added the real plants not only for the humidity, air quality & asthetics, but also b/c veilds are known to eat plants as part of their diet. I've heard that panthers are also known to take chomps out of their plants on occasion, but not as often as veilds. I'd say it may be a good idea to use at least one real plant to give the cham some greens to munch on. You can also offer some greens clipped.
I don't know how common it is for panthers to ingest fake plants, but if you are worried about it, you can offer some real ones.
I'm not sure how much of a help that all was. I'm sorry your friend lost her(?) cham. =(
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1.1 Crested Gecko (Anton/Angelina & Harley)
1.1 Crazy dogs (Alex & Sadie)
0.2 Vacationing Kitties (Puddy, PeeWee)
0.1 Amazing Wife =o)
Charlie - RIP 9-8-05 (Veiled Cham)