My engine oil fluid is slightly over the max mark - maybe 0.5" - 0.75"
Dealer said it is less than a quart, even though it shows as 0.5" - 0.75"
They did a 30point inspection and it was not brought to my attention - he said it is not an issue. What should I do - this is a 2013 mazda5?
While the actual height of oil over the max mark is vague, the dealership is probably right. If it gets too full the crankshaft whips it as the engine turns, which causes problems. But just slightly over is not going to cause that problem.
If you’re really concerned, just drain a little bit out.
Why? Who changed it?
Was the oil drained and filter replaced?
How was the oil measured that was put into the engine to refill it?
Did whoever refilled the engine with oil put in the amount required in the vehicle’s capacity specification?
That .5" to .75" is fairly meaningless without knowing how much oil volume it represents. It could be 6 ounces. It could be a quart. Who knows?
I always over-fill my engines by about 8 ounces (by factory specified capacity) whenever I do my oil changes. I’ve been doing that for hundreds of changes over many decades.
CSA 
A shop changed the oil/filter.
Okay. Sorry… Based on the information provided (or lack of it) there are too many variables for me to make an informed opinion and I really doubt anybody else can help you. It’s anybody’s guess.
The car’s manufacturer specifies the oil capacity (usually with or without filter change) and usually includes an admonition concerning over-filling the engine. That’s what one goes by.
CSA