I do know something about this. I have been in healthcare-direct pt care-usually critical- for over 20 yrs. I'm pretty good at what i do.
when an IV-intravenous cather-is inserted-you draw BACK on the syringe, making sure you get full blood return THEN attempt to "push" a small amt of solution into the vein of the person. this is done to "test", making sure catheter IS CORRECTLY inserted, IN the VEIN of the patient, & also that the site, vein, will not "blow"- which is a rupture or weakness of the blood vessel.
If something is WRONG, it's immediately & graphically apparent. there is NO WAY they could NOT have known.
In addition, all IV's are put on a "pump" which really does not PUMP- it regulates volume and more importantly RESISTANCE, iwhich is much greater IM(intramuscular) than IV. The pump will stop flow & alarm, alerting someone IMMEDIATELY that something has changed.
The SITE is no longer good. this prevents IV INFILTRATE.
If fluid continues to flow, with a dislodged IV, fluid will go into surrounding tissues. This also is IMMEDIATELY apparent. It takes MUCH, MUCH(sometimes days) longer for the body to absorb chemicals that go into surrounding tissues.
SO, whether its manual or pump related, makes no difference. There is NO WAY they could NOT have known immediately- not only that "something" was wrong-but, EXACTLY WHAT was wrong, AND the adverse results.
Hope this helps. I'd be more than happy to be more specific. Anything MEDICAL issues or discussions, I might have something valuable to contribute(even ethics/regulations) .