Matthew 28:14

‘And if this come to the governor's ears, we will persuade him, and rid you of care.

The problem with such a story for the soldiers was that it might reach the governor's ears, which would not please him very much. And they knew that they had been acting under his instructions. But they were assured by their employers that they would then see that everything was all right for them. They promised that they would use their influence, and probably more money, in order to ensure that there were no repercussions. Had these been Roman soldiers we might in fact have expected their fear to be that their Commanders found out (Pilate would have returned to Caesarea, or would be on the point of doing so). It was they who would be directly responsible for disciplining such a failure. It is very unlikely that they would have believed that their commanders could be bribed. Thus again we have the impression that these were the Chief Priests' soldiers.