Seemed clear enough to me ... and do the de-icers have to share the taxyway with aircraft to get from T4 to T5? Or did someone think it through and build a service road?
I have this vague feeling that T5 was a flawed concept from startex. The lack of real estate, ramps/piers/whatever ...and yesterday's DT says that there may be fewer regional flights into LHR, so that unless you live in Surrey or West Lunnon you won't be able to get to an international flight without substantial aggravation.