Please help to understand

[Ismq]

Shalom, we read in Job 1:20: 'At this, Job got up and tore his robe and shaved his head. 
Then he fell to the ground in worship' when he had learned about his family members having been killed. 
It was very tragic for him of course. 

My question is why did Job shave his head when the verse in Leviticus states the following: 'Do not cut the hair at the sides 
of your head or clip off the edges of your beard.'- Leviticus 19:27?

I have heard that the reason the command in Leviticus 19:27 was given is because the pagans of that time cut their hair in a pagan ritual for their dead. Why did Job shave his head in that instance when the verse says one ought not to?

thank you and blessings.

Forbidden under the law of the jews leviticus 21:5 deutoronomy 14:1 but widely practised by the gentiles isaiah 15:2 jeremiah 47:5 and 48:37.