- The 2nd one is to do a CPFP with high fee if you have full control of the receiving address you can do this.
If he used like just 1 inputs and 2 outputs, there is not need for this because the transaction woukd have been confirmed or will still be confirmed.
- The 3rd one import your backup phrase to Electrum and bump the fee.
He will not be able to do that if the transaction is not supporting replace-by-fee. Unless he tries to look for node that is supporting full RBF. I have not done this before and I do jot know how it works because all my transaction is supporting replace-by-fee.