Very strange ?? Best and biggest plant most roots / just shrivelled up??? Why? HELP

Help needed, my best plant with the biggest roots shrivelled and fell over, all roots were really white, only thing I could think is it went really close to my air cooled reflector and the top got a little burnt, would that kill the entire plant? Pls see pic of roots

I'm sure you stunted the hell out of the growth and will take a while to bounce back, but just by looking at those roots they still seem healthy. Give her time