More may be added to the earlier biography.
At an uncertain date before 1418 Trewint came into conflict with the unruly Adam Vivian*. The details of the dispute, which the two men submitted to the arbitration of Sir John Arundell that summer, are obscure, but it seems that the attempt at mediation came to nothing, for in the autumn of 1419 Trewint brought fresh litigation against his opponent under the terms of the bond guaranteeing the arbitration.
It is unlikely that Trewint’s dismissal from the office of coroner in 1421 resulted from his poverty. His holdings at Trewint, Launcells, ‘Pendreyf’, Trevysyk and elsewhere in Cornwall still extended across some 200 acres.
Trewint’s extensive parliamentary experience provides sufficient explanation for his choice by the burgesses of Lostwithiel as their representative in Henry VI’s first Parliament, and it is thus likely that the recording of his name over an erasure on the schedule accompanying the sheriff’s indenture was a result of scribal incompetence rather than of any deliberate deception.
Although Trewint left no legitimate issue, he had a bastard daughter, Elizabeth, who married the lawyer William Skenock*. In his lifetime Trewint entrusted his estates to Nicholas Aysshton* and Thomas Roscruk*, with instructions to settle them on Elizabeth and her descendants, should he die without legitimate heir.