Everything has been in chaos at the office since this morning ㅠㅠ

Our company uses a type of mold during product production. We purchase metal and send it to a molding company; they melt it, shape it, and deliver it to us. We then fill it with raw materials and heat it to create the final product. Once production is finished, we remove the mold and send it back to the vendor, repeating this process.
The problem is that the material used for these molds is quite expensive. The platinum content is also quite high. Naturally, we manage the weight during both inbound and outbound processes and use custom-made cases.
However, we just received word from the vendor that there is an issue.
To give you a simple example, our outbound inspection weight was 10g, and the vendor's inbound inspection weight was also 10g, but when the mold was actually manufactured, it turned out to be 9.9xg. At first, we let it slide, thinking it was just production loss, but as this accumulated over the third quarter, the discrepancy became significant. Suspecting something was wrong, the vendor began measuring the weight every three hours after the inbound inspection. They reported that after about 12 hours, the weight had decreased by 0.1 to 0.2g. What's even stranger is that this phenomenon only occurred with goods brought in by a specific employee of ours.
The manager dragged that employee out of the office as soon as they arrived, and we are currently exposing all the data they were involved with and conducting a full inventory audit. I have no idea how someone could make the weight change after 12 hours, but seeing as the vendor sent over documentation that is almost at the level of a formal report, it seems like someone was definitely tampering with things. I used 10g to explain it simply, but it seems the actual amount amounts to hundreds when calculated by unit cost.
It's total chaos. Absolute chaos.