will

Imagine the Combine's confusion when Freeman raids Nova Prospekt. You can hear radio chatter while you storm the coasts of Nova Prospekt with the antlions, and the Combine sounds so confused because they see the perimeter restrictors disengage, followed by radio silence from their outposts, and then they identify Gordon Freeman and buttloads of antlions. Later on in the chapter, you hear them on the radio discover Gordon is actually controlling the antlions and they really start panicking. I imagine that when they were hunting Freeman along the coast, they were expecting him to just be trying to get into hiding instead of raiding probably the most secure Combine base on Earth. Bonus detail, when you meet up with Mossman in the Depot, you hear on the radio that Nova Prospekt has completely fallen and only the Depot remains functional.