Shock! Disbelief!

Previously, the commander had only thought that the robbers might use some items to hide the bugs such as the smelting furnace like last time or something like that.

So, he had only looked around for big subjects that the robbers could use.

He had never thought that Jon would plant the bugs under the table and the temporary command room.

He never thought that Jon would put the bugs in these two places.

So, even if he wasn't eliminated by the robbers, he wouldn't be able to find the bug.

Unless he scanned it with the equipment, he wouldn't be able to find it.

However, since Jon installed the bug in the temporary command room and under the desk, that meant that it wasn't that Jon didn't install it right after they left the bank. Instead, they came back to install it after the temporary command room and awning were built.