Working loose appears to be the problem.
The Dayton, Nevada, newspaper carried an item after the pipe frames had been in service about a year. It said that they were not holding up in service as well as the traditional wood framed cars.
La Mothe cars were built for eastern standard gauge lines and also for lines in England. But they do not seem to have lasted long. Kyle Wyatt, now with the CSRM, has reported that by 1890 the railroad press was reporting that lines were refusing to accept the pipe frame cars in interchange.
My understanding is that the cars on the C&C/SP were more difficult to equip with air brakes and standard grab irons.
What is remarkable is that two cars bodies that went on the ground in Mina, Nevada, about 1906 are still with us. Both in the collection of NSRM. The more complete one is undercover and one that partially burned prior to acquisition is stored off property. The partially burned one best shows the overlapping joints of the side panels.
Brian Norden