I’ve personally never witnessed this, and I’ve worked in government and know people who work in government in other contexts, and I haven’t ever heard of an actual anecdote to that effect either.
I’m sure it exists, but the meme seems overblown. From what I’ve seen, government is more frugal than the private sector day to day, the main difference is that the government ends up supporting unprofitable programs and has additional burdensome regulations that drive up costs (eg buy American)