In the Breaking Bad episode where Walt plants the bomb on Gus's car, Gus stops dead in his tracks. After rewatching, I noticed that Walter goes home and calls for his neighbor to go inside and check out the house because Walt Jr. "left the burner on." His neighbor goes inside and checks the stove, and two men leave the backyard. Walt then runs in from the back and gets his money. The men return, and they walk in, down the hall, and past the kitchen. Walt already has the pipe bomb made; it's in his baby bag.
After Walt blows up Gus, he comes home and cleans up the evidence; the bomb was already made, which means the evidence was laid out in the kitchen and the two men walked right past it, which was obviously the makings for something dangerous, yet the two men didn't notice it.
I feel like this is a big hole in the story. Please, can I get some feedback or something? I'm not sure what to think of this. Was this really a plot hole, or is there some other explanation for it?