Black oncidium root tip?

[Bulbopedilum]

My oncidium grew a weird root that went up a pseudobulb. After a few days, the root tip went red. I thought it was normal. But now the root tip is black. Did it get burned because it climbed up the pseudobulb into the air (is it supposed to be a normal root that wandered off)?

[estación seca]

They grow like this sometimes. If the root tip gets too hot, dry or sunburned, it blackens like this.

[Bulbopedilum]

Dry is probably the explanation. I never top water, I just dip it in my fishpond