I have a needless injection system, uses a compressed gas to force the insulin thru the skin.....mind you had t fight to get it and not too common on the good ol' NHS.
The resting equipment does use a needle to prickthe skin and draw blood but it is so tiny one can hardly see it. Although In have a doctors note, I've never once on any airline been questioned about them.
Seems a bit of a storm in a tea cup really as someone quite rightly pointed out early, if using needles, then diabetic's needles are infact tiny and most use a pen dosing system which is totally harmless, less dangerous than a bic biro!
Does seem like BA are being a but strict here especially when other airlines arent, and I've never seen anywhere where its written down or displayed that you can't carry a dosing pen or testing kit.
This is one area where common sense ought to prevail as it's not the first time it's happen and probably won't be the last.