Because that can be a red flag.  

He was soooo deep in the red ON PAPER, and didn't know what to do.

I just paid my attorney 15k today in just fees for 4 entitlement contract red lines and we arnt even under contract yet!  

or perhaps a reverse build to suit where the data center operator controls the buildout and the planning etc.I've not been involved in a data center first hand but the central OH market is pretty data and warehouse heavy as far as developments go and to echo the posts here, the power requirements are wild, and the red tape to get that power to the site is often cumbersome. 

The property is a duplex with an ARV (after repair value) of $700,000, making it a strong deal.However, I want to ensure I’m not overlooking any potential red flags.

Red flags all the way around. 

It is very unlikely that you'll have problems/be investigated for just one instance, but repeatedly doing this will absolutely raise red flags these days.

Are there any potential red flags I should be aware of?

Now, my thoughts (full disclosure: I am not selling you anything): I see it as a red flag that the GP is doing a capital call, but you don't know why.

Any GC that does not work like this is a huge Red Flag and you should run away.2) Also any experienced GC should have theur own state-legal contract that spells out terms clearly and protects both of you.