I had one misfire as I was removing the cap said...
That's what happened to me recently too! Pulled off cap 1 and found I was holding the needle and the glass tube in my other hand ... and $750.00 worth of medicine drippling on the floor.
My husband is convinced I twisted the pen when I removed the cap. The Humira representative told me it often happens.
FYI ... if that happens; hang onto the pen and the box in came in (with the lot number). Call the pharmacy that you purchased it from ... then they'll have you call the pharmacutical company (is it Abott?) ... and after an act of congress and promising them your first born child, they'll send a replacement ... PLUS a bonus pen to cover you in case it happens again.