[Tenant - CA, US] Gas leak issue

Hello! My gas was shut off due to a gas leak and it took my landlord 3 weeks to fix. We were kept in the dark about any fixes and when it would be finished. After the gas company turned the gas back on I asked the landlord when and by whom the gas leaks were fixed by and he said that there was no service done on the house after the initial inspection.

This raised a lot of questions so I took a look at the lines and it looks like someone taped up the area where the leak was. I suspect the landlord taped it himself without our knowledge to save money on a plumber.

Is this illegal? Wouldn't he need a permit or license to fix gas leaks? I'm worried that this fix is only temporary and we'll have a leak again.