Why didn't Coulson call SHIELD when he got wind of Stane planning to wipe out Stark?

Question

In Iron Man (2008). So, Agent Coulson is trying to get an appointment to debrief Stark after his escape from the desert. SHIELD probably knows about the technology, or have a good idea of it.

Stane makes Potts uncomfortable back at the office, and as Potts is running to get away from Stane she runs into Coulson, and decides to spill all the beans on Stane.

Potts, along with Coulson and 5 other agents, show up at the lab where Stane is doing an experiment which has the potential to be catastrophic.

Here's what I don't get:

The 5 or 6 agents go in knowing they would likely face some enemy that was at least as tough as Stark. We know by the post-credits scene that Stark isn't alone and that SHIELD is tracking many similar potential heroes.

So, finally, my question is; Why didn't Coulson just call Nick Fury and ask for a few backups because the enemy was overpowering?

Answer 1

Why didn't Coulson call SHIELD when he got wind of Stane planning to wipe out Stark?

Because he didn't know!

At this stage all Pepper knows, and thus all she can tell Coulson, is that Stane has been selling arms illegally and, perhaps, trying to build/design "a suit" which in itself is not illegal.

They don't know that Stane has stolen Tony's chest reactor which is the only thing that could power the supposed suit.

They don't know he's actually built a "working" suit...indeed when they first come across the remnants of Tony's suit they think that's it...Pepper says..

"I thought it would be bigger"

So, all they are there to do is arrest Stane for illegal arms sales and you don't need more than 5/6 agents to do that.