antihelp

to actively hinder, either maliciously or through ignorance, someone elses attempts to reolve an issue

Despite his antihelp about the breaker panel, we managed to bypass the failed UPS within an acceptable time frame.

Antihelpful

antihelpful (adverb) the act of going above and beyond unhelpful making things worse:

Detrimental deleterious

A member of the committee is being antihelpful spouting rhetoric instead of
coming up with new ideas and solutions.

See also antihelp antihelping