Literally in my last couple shifts I've had:
"Suspected Addisonian" - I took one look at the labs and recommended just rechecking them - yup, lab error, easily could have been done at the rDVM if they talked to me about the numbers prior to transfer, instead I get to gently manage the owners being pissed they got sent to the ER and charged another exam and lab fee.
"Needs Blood Transfusion" - I have no blood in my fridge. I have one donor dog remaining on my list, and your patient is a 60lb IMHA with a PCV in the tweens... this ain't the place for this patient (who also got no estimate, didn't realize blood transfusions weren't an outpatient procedure, etc...)
"Heart failure cat" - yes I can tap the cat's pleural effusion. I absolutely understand that being a lot more stressful to do if you don't have ultrasound and don't do it often. But please have a discussion about the guarded prognosis for most causes of pleural effusion, the need for hospitalization/medication even in "good" causes, and if the cat is turning purple at your clinic I really would prefer you poke them so the 45 minute drive doesn't kill the cat. Because sometimes it does, and that situation is horrific for everyone involved, most of all the cat.