Is your complaint that T5 isn't working or that the staff didn't know what they were doing?
Spot on but BA are currently spending £££'s telling us that T5=BA=pleasant experience and, when it works, it is but at the first sign of trouble they don't appear to have a clue.
Your post reassures me that it's not the norm but a responsive Customer Service team in the event of difficulties rather than Jobsworths with clipboards would do far more to encourage me to continue using it.