If I select some but not all of my ships I lost in battle to recover, it does not stop to warn and confirm before salvage.
Three ships die in one battle, two were valuable high-tech ships that are in my fleet in all times. A third ship was an Enforcer I picked up and armed with loot from a recent battle. I selected my two high-tech ships, but left the Enforcer to rot (because it already had d-mods). It proceeded to salvage without warning, which was okay this time. But I can see losing a ship if player is not careful or alert enough.
Without the prompt, it can be easy enough to miss ships, especially if some end up in difficult recovery while others do not. I might have lost a Gryphon this way (and I cannot remember if it had s-mods on it). After that combat, I lost about half of my fleet and recovered an enemy Paragon and all of my ships... except a Gryphon that somehow slipped through the cracks. I do not remember if the Gryphon ended up in difficult recovery or if was one of the rare cases of not being recoverable at all (it was unofficered, but I had Hull Restoration) despite near guaranteed recovery.