Walter had no idea when he started being followed, though he had indeed been manufacturing drugs in the lab beneath the laundry factory recently. The photos in his hand covered three days, but he wasn't sure if there were more.
The key was that the laundry factory had not been under lockdown before. After Jesse killed Gale, Gus came only once and never appeared at the laundry factory again, but Mike and others showed up many times, along with Jesse.
Walter wasn't sure if Jimmy had discovered the lab beneath the laundry factory. If they only found out they had spent a few hours there, saying too much could lead to something more serious. Gus, the demon hidden under the guise of a businessman, who knows what he might do; maybe even his family would be in jeopardy.
Walter's hand unconsciously clenched tightly, creasing the photos in his hand, but he remained silent.
