In testing with the iPad Pro, the User Agent string is being reported as:
Mozilla/5.0 (iPhone; CPU iPhone OS 9_1 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko)
Mobile/13B143 (5844012048)
If I use Safari instead, then I get:
Mozilla/5.0 (iPad; CPU OS 9_1 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Version/9.0 Mobile/13B14 3 Safari/601.1
All other iPads behave properly and report iPad in both places.