I used to work for a company where we made test rigs and their safety guys were strictly against having a single machine with multiple power inputs. It wasn't about power draw. Once you have two plugs:

1. You no longer have the nice property that unplugging it guarantees (more or less) that it isn't electrified.

2. You open up the possibility of mains voltage from one plug appearing on the unplugged prongs of the other plug.

3. It possibly messes with RCDs, depending on what you do exactly.

Although in this case it's probably fine because he's just plugging totally separate power supplies in and they're already fully enclosed.