[6] His brother-in-law is former Texas state representative Kevin Roberts, who ran against Dan Crenshaw in the 2018 Republican primary to replace retiring Congressman Ted Poe.

A Matagorda County, Texas jury found that Amoco had wrongly backed out of a contract to sell Wyoming oil fields to Rubicon.

[9] In the 1998 trial of Aaron v. Abex, Lanier was the lead counsel for a group of steelworkers who contracted asbestos disease at an Alabama steel mill.

[11] In 2005, Lanier represented Carol Ernst in a lawsuit against Merck & Co., a pharmaceutical company and manufacturer of Vioxx, an anti-inflammatory drug used to treat osteoarthritis and acute pain conditions.

In another case Lanier obtained consumer fraud findings against Merck who it was claimed had misled doctors and patients by concealing information about Vioxx and its risks.

[12][13][14] The first ruling was overturned on appeal in 2008 with the court noting Lanier "had not proved that Vioxx caused Mr. Ernst’s death" and compensatory damages were reduced in the second.

[18] In March 2016, five North Texas residents being represented by Lanier were awarded about $500 million for alleged complications arising from the hip implants.

The lawsuit alleged that the company's talcum powder products contained asbestos and that, after several years of use, had caused each of the women's ovarian cancer.

[34] In late 2019, Lanier represented Summit and Cuyahoga counties in the first trial against pharmaceutical companies for damages caused by the distribution of addictive opioid painkillers.

The lawsuit claimed that the drug distributors failed to monitor sales as required by federal law and report suspicious activity, which contributed to opioid addictions.

Hours before the start of a trial, three pharmaceutical distributors and a manufacturer reached a settlement $260 million to resolve litigation over damages caused by the opioid epidemic.

[35][36] Lanier also represented Trumbull and Lake counties against retail pharmacies for excessive distribution of addictive opioid painkillers.

[37] The lawsuit alleged that pharmacies operated by CVS Health, Walgreens, and Walmart created a public nuisance through the over-prescription of pain medication in those communities which contributed to hundreds of overdose deaths.