I think they are referring to the time they are paying for.
IIRC engineers tend to be salary rather than hourly so as long as the get the assigned work done they may try to claim they were not engaged in “theft”.
But the natural counter to that, unless you are a real Wally, is engineering is not merely a 40 hour job.
A big trend in IT Engineering is contractors that work on hourly rates. In fact, I would say the mix is like 40% contractors to 60% full time employees, especially in large fortune 100 companies. They hire outside contractors to work specific projects in varying length, then either assign the contractors to new projects or get rid of them without paying unemployment compensation etc...
For the last 15 years of my work career, I worked exclusively on hourly wages.
I personally knew a few engineers that were working multiple jobs at the same time, the problem was trying to keep things straight and hours required to complete each job, it eventually wore the engineers out and eventually they all gave up one of the jobs.
“a real Wally”
??
If the guys got their work assignments done, I’d vote not guilty.