There will now be a delay in the inevitable overruling of Browning-Ferris, 362 NLRB No. 186 (2015), which had made it easier to determine that two employers are joint employers under the National Labor Relations Act.
In December 2017 the NLRB issued a decision in Hy-Brand Industrial Contractors, 365 NLRB No. 156 (2017) which overruled Browning-Ferris.
The problem was that Member William Emanuel had a conflict of interest. This is all detailed in the NLRB's Inspector General's Report [PDF]. Then the Board’s Designated Agency Ethics Official determined that Member Emanuel "is, and should have been, disqualified from participating" in Hy-Brand. As result, the Board has vacated Hy-Brand. Hy-Brand Industrial Contractors (NLRB 02/26/2018) [PDF].
This is not the end. This is only a delay. The Board will overrule Browning-Ferris – after the Republicans regain the majority they lost in December 2017.