Water and electricity?
Unfortunately water can be bad for electronics in several ways:

It can create shorts between signal wires, causing logical errors or destroying chips that suddenly have unexpected voltage levels.

It can short out power lines, causing heat that can burn up parts of the device or disable the battery.

It can corrode metals, possibly causing the above two problems now or later, or changing the electrical characteristics such as resistance or capacitance with hard-to-predict results.

Water drops on the loose inside the device could also move around as the device is handled.

To be certain the device won't develop problems later on, it should be opened up, inspected and left to dry out. Then again, it might be fine as is. It's just really hard to tell from the outside.