Any other noise may have got attention on your way out.
One thought would be to find where he enters property,or if he stays on it where to intercept him before dark. Only when site is in your favor regarding wind. Sounds like a ground hunt may be in order. Take care to have a background to avoid your profile being seen. if its been awhile practice shooting ground level too. Good luck on closing the deal. Glad they don,t hunt us hard!