Normally, in the rainy seasons (due to moisture in the environment) there is accumulation of Moisture on the card and also around the picture tube (in ur monitor) so due to this , the connector is also moisturised..
This can be solved by just unplugging and replugging the monitor cord tat goes at the back side of ur monitor and it will solve the problem. (i hv tried it and it works for me.)
If he opened the cabinet, then he must hv unsocketted and resocketted the AGP card and cleaned it with a cloth to remove the moisture (coz of the damp weather). So there is nothing to worry about. Sumtimes u will get a hazy appearance while switching ON ur Monitor and after sum time the haziness (blurr effect) will go away, this is simply bcoz as the picture tube (CRT) warms up, then the moisture goes away.
I hope my explaination was helpful to u..
Cheers n e-peace....