tenant complaining about damaged window, claims mold, not paying rent

[Ryan F.]

Tenant started to paint apartment walls (I gave permission), peeled back some old paint around a window, and noticed the wood window frame was rotted. It appears to have been damaged by water some time ago, but the area is completely dry now and no leaking presently. I am doing everything I can to repair/replace the damaged wood as soon as possible, but he is claiming there is mold and refuses to pay anymore rent until it is fixed. If the window did leak years ago, and the problem was fixed on the outside but the interior wood frame was left, is there any possibility at all that there could be mold? I always thought that if there was no water, there is no mold. Even if there was mold on the frame at one point, if it has been completely dry for years, is there any chance it could be dangerous and/or show up positive on a mold test?