Thank's for clarifying the question. I think the employee isn't fully aware of how hybrids work. To first state the well known, regular cars (i.e. non-hybrid) use a 12V battery and a starter motor to start the engine. If the 12V battery is dead then you need to get a jump start from another car, or use a portable jump start battery. Hybrids also have a 12V battery but it is only used to power up the electrical system, after which the actual starting of the engine is done by the HV battery. It would almost never happen that a healthy HV battery would not have enough power to start the engine after sitting for several weeks. Even if the battery is near 0 it actually has a large reserve that the system maintains. In theory an older HV battery (many years old) or one that is defective might fully deplete after many weeks or months of sitting idle, but that situation normally happens only at dealerships where unsold cars can sit for up to a year, and not all dealers properly maintain the HV battery during that time by keeping it charged.
However just like a regular car, if the 12V battery goes dead then a hybrid won't start either. Most hybrids use a standard 12V battery, and the lifespan and propensity for failure is the same. If that happens the solution is the same, you get a jump start. And I mentioned using a portable battery, those don't always work on a regular car because portable batteries come in different ranges of cranking amps (normally related to the price and size of the portable battery) and depending on the situation, i.e cold weather, large engine, etc. it may not have enough power to start the engine. However since with a hybrid the 12V system is only used to activate the electrical system, even a small relatively low powered portable battery will almost always be able to activate the 12V system and allow the HV battery to then start the engine.