Before we embark on a round of classic FT speculation-sans-facts, it seems to me that we also have no idea how many people actually miss (or even delay) their flights because they're stuck in lifts.

But one thing can be guaranteed: If BAA were to require that there be a dedicated full-time lift engineer at T5, there will be complaints on FT that BAA is skimping - for the mere and shoddy aim of saving costs, dammit! - by not requiring a full-time lift engineer at each of T5A, T5B and T5C, and thereby making some of the pax stuck in lifts have to wait 10-15 minutes for the sole resident T5 lift engineer to make their way over to the affected lift. Doesn't BAA know these pax have flights to catch?