Can warm weather and sun (25 degrees celsius or 77 degrees fahrenheit) cause cracks like these?
More detailed backstory. I sent my car to a company for 3 layer polish. Got it back, left it in a garage for half a week until I sent it to a local workshop to replace a part that eventually never arrived. I got it back 5 days later, then noticing these cracks in the paint.
The workshop claims that due to no clear large physical damage, it cracked due to simply hot weather. Only by coincidence while staying (outside) with the workshop. Also a comment that it probably was a bad paint job, probably using a primer not meant for plastic (the hood is made of plastic).
The car is a 2000 model, and was repainted 8 years ago (2013). It is parked outside for 6 of those years.
Is my workshops explanation probable?