Why did your laptop get the boot instead of being stored under the seat in front of you? Bulkhead?
Secondly, was it in a regular laptop bag or some kind of other setup? UA's liability page says this:
United is not liable for the destruction, loss or damage of any baggage caused by:
- Inherent defect of baggage
- Poor quality of baggage
- Baggage being over-packed
- Ordinary wear and tear
Makes me think a regular laptop bag may be considered "poor quality" given that it's not designed to be checked to begin with...