Good thing that it doesn't died, and still ok except for the sunburn.
the same thing happens to my only orchid at my house. At first I thought it was seated by some slug or snail, until one morning I realized that it was my fault to not notice that it got exposed to too much sunlight.
Yea, so far so good. I am counting on some flowers this year too :)
Orchids are equally sensitive to sunburns. Not many can handle the direct sun - most grow among trees so they are shaded.