I disagree. Showing a pattern of what appears to be discriminatory behavior does indeed help to prove a discrimination case. Indeed, you see evidence of that kind of pattern used often in these kinds of lawsuits. If it's just a single employee the employer will offer up some nondiscriminatory excuse for firing the employee and that may be hard for the employee to rebut. But when the employer has been letting go a lot of older employees at rates significantly higher than younger employees that makes it easier to argue that the employer's supposed justification for the termination is a lie and that the real reason for the termination was the employee's age. It's easy for an employer to say one older employee is crappy with a straight face even if he wasn't crappy. It's harder for the employer to say that all those older employees that were fired were crappy while the younger ones weren't. As a federal district court explains:
The defendant also argues that information regarding prior complaints is not relevant. The plaintiff contends that the information is relevant to the defendant's motive and intent and to the plaintiff's argument that the defendant's reasons for firing him were pretextual. The court agrees. “Evidence relating to company-wide practices may reveal patterns of discrimination against a group of employees, increasing the likelihood that an employer's offered explanation for an employment decision regarding a particular individual masks a discriminatory motive.” Moll v. Telesector Res. Grp., Inc., 760 F.3d 198, 204 (2d Cir. 2014) (quoting Hollander v. Am. Cyanamid Co., 895 F.2d 80, 84 (2d Cir. 1990)). See Lieberman v. Gant, 630 F.2d 60, 69 (2d Cir. 1980)(“Evidence of general patterns of discrimination by an employer is relevant even in an individual disparate treatment case.”); Carter v. Logan Bus Co., No. 15CIV5217ENVJO, 2016 WL 5231800, at *2 (E.D.N.Y. Sept. 21, 2016) (affirming magistrate judge's order requiring discovery concerning other employees and noting that “[d]efendants seem to confuse pattern-or-practice discrimination claims, which are not at issue in this case, ... with the routine use of circumstantial evidence of a pattern of discrimination to support an individual disparate treatment claim, see Hollander, 895 F.2d at 84-85.”); Sasikumar v. Brooklyn Hosp. Ctr., No. 09 CV 5632, 2011 WL 1642585, at *3 (E.D.N.Y. May 2, 2011) (holding that “courts in this circuit have repeatedly found similar complaints of discrimination by corporate employers to be relevant and discoverable” and granting motion to compel defendant to produce complaints by employees of defendant's nursing department alleging discrimination and/or retaliation based on national origin, race, color or age for the years 2001 to 2005); Culkin v. Pitney Bowes, Inc., 225 F.R.D. 69, 71 (D. Conn. 2004) (“Evidence of general patterns of discrimination by an employer is clearly relevant in an individual disparate treatment case and is therefore discoverable pursuant to Fed. R. Civ. P. 26(b)(1).”)
Huminski v. Stop & Shop Supermarket Co., No. 3:16CV1136(RNC), 2017 WL 2779468, at *2 (D. Conn. June 27, 2017)(Bolding added.)
Bottom line: evidence that points to a pattern of discriminatory treatment of older employees is relevant in an age discrimination claim and is useful in proving that the employer discriminated against the plaintiff employee.