Did you see my face?

There was this small village bank which was held up on a friday morning. Apart from the robber, and the teller, the only other persons present in the bank, was an elderly couple.
When the teller handed over the bundles of money, the robber discovered that he had forgotten to pull his skimask down over his face, and before leaving the counter, he asked the teller, -"Did you see my face before I masked myself?" -"Ye-ye-yeeesss sir... aaaah-aaa..", stottered the teller, upon which he was immediately shot dead by the robber. Turning around to the elderly couple, the robber, addressing the old man, -"I am not leaving any vitnesses!... so, did you see my face, old man?" -"No sir, I didn't... but my wife did!"