Items lost within the ride envelope should be noted on the ops log and located overnight to be returned to lost property. The guest should be told to come back tomorrow to claim it.
The issue with a phone is it's a bit more important to get back than a hat or sunglasses, and if it isn't located immediately while the person who lost it is there, what's to say it'll be found after hours \ in the dark?.
It's lose\lose for the park no matter what they do. And yes, the guest should get what they deserve, but it's not in the interests of the park's guest relations to give them the finger.
ETA: After posting, I was reminded of the landing pad below the station on the SFMM Green lantern (I think it was a Zacspin \ 4D?). Anyhow the final hairpin before the station was so forceful, violent, and with such a sudden stop, it was clear loose items didn't stand a chance - there were at least a dozen devices in various states of disintegration (all of them fresh though), a couple wallets and some glasses.
Ops didn't stop for them... and such is life.