It's not DELTA that would reject the skates, it's the TSA, which is independant. Granted, Delta lost her luggage.
I flew out of JFK last May with two pairs of Klingbeil skates in my carry on. I usually check a bag, but I didn't that time for various reasons. The TSA agents didn't say a thing and let me through with no problem, which really surprised me.
I arrived prepared with a printout of the TSA's list of banned items - figure skates aren't on the list of sporting goods. I told the TSA agents that I had figure skates in the bag, so they wouldn't be surprised. They do look dangerous on the x-ray, like big knives with pointy things at the end.
The TSA agents are capricious, though: some friends have said that the TSA agents at other airports didn't let them bring the skates a carry-on even with the list since skates AREN'T on the list of "Okay Items." Too bad your friend didn't think to ask to have the skates gate-checked rather than letting them be tossed out; that's what my friends did on their way to competitions.
Did you friend have hard guards on the blades? Without guards, they are weapons or at the least, something dangerous that could fall out of an overhead and hurt someone. I put hard guards on both pairs, using twist-ties to secure them in place.
Sorry for her loss, but new skates are always nice. How long ago did this happen?
PS - A woman started to leave with my bag of skates! She didn't speak english, so it was hard to explain that she had the wrong bag. She mistook my PSA bag for her own carryon, which was in the next overhead compartment.
When I saw her bag, I knew it was a simple mistake. Can you imagine her reaction when this 70-year old granny opened what she though was her bag and found ice skates? She laughed all the way off the plane when she saw what my bag contained.