Circuit Nodal Voltage
After further reading into non-ideal op-amp behavior it looks like it's actually the op-amp input bias current that's the culprit.

R1||R2 ~= 100kohm, which created about a 0.6V drop (close enough to what the difference was). Adding a resistor to the inverting input equivalent to R1||R2 fixed the problem.

Reference:
Practical Considerations: Bias current

The fixed circuit: