Supreme Court held that, even after getting discharged, an accused can be made to face trail u/s 319 CrPC, if new facts/evidence emerge during trial, even at chief-examination of prosecution witnesses.

From Para 6,

6.2 Considering the law laid down by this Court in Hardeep Singh (supra) and the observations and findings referred to and reproduced hereinabove, it emerges that
(i) the Court can exercise the power under Section 319 CrPC even on the basis of the statement made in the examination-in-chief
of the witness concerned and the Court need not wait till the cross-examination of such a witness and the Court need not wait for the evidence against the accused proposed to be summoned to be tested by cross-examination; and
(ii) a person not named in the FIR or a person though named in the FIR but has not been charge-sheeted or a person who has been discharged can be summoned under Section 319 CrPC, provided from the evidence (may be on the basis of the evidence collected in the form of statement made in the examination-in-chief of the witness concerned), it appears that such person can be tried along with the accused already facing trial.

6.4 In the case of Rajesh v. State of Haryana (2019) 6 SCC 368, after considering the observations made by this Court in Hardeep Singh (supra) referred to hereinabove, this Court has further observed and held that even in a case where the stage of giving opportunity to the complainant to file a protest petition urging upon the trial court to summon other persons as well who were named in FIR but not implicated in the chargesheet has gone, in that case also, the Court is still not powerless by virtue of Section 319 CrPC and even those persons named in FIR but not implicated in chargesheet can be summoned to face the trial provided during the trial some evidence surfaces against the proposed accused.

Citations :

Other Sources :

https://www.indianemployees.com/judgments/details/sartaj-singh-versus-state-of-haryana-anr-etc