No proof of LTE + voice necessary. It simply is. Every other LTE phone in the world, from the crappiest Chinese Android phone to their flagship models, support simultaneous LTE data & voice. If the iP5 doesn't, Apple is the stupidest tech company on the planet (since the Qualcomm chipset 100% supports it).
If it doesn't do LTE+voice, I'll post my ATM card number and PIN here on this forum.