I didn't even make a counter offer to his offer.

What would happen if both sellers accepted the offer without a counter offer? 

Then I find out that it went into escrow yesterday for $670K..seller didn't even bother with a multi-counter offer.

Is there any way to throw a feeler out there (e.g. would you be willing to knock off $10k since we have to do all these repairs) without officially making a counteroffer or re-opening negotiations?

If you have to go higher for a counter offer, tell your realtor you padded in $5000 on your offer.

I also have the time between when they are accepting the offer or giving a counter offer to look.

It would be my first deal, I haven’t contacted the wholesaler yet to maybe counteroffer, just wanted to see what you guys think of the numbers.

Honestly, I was sidetracked by their discount request and not wanting to lose them as they are wonderful tenants, that I didn't even consider making a counteroffer of offering to keep rent same rate at the time yesterday. 

However, if your post virus analysis tells you you will lose a more if you close...and continue to lose more, then bit the bullet...and don't close.Now, as far as making a counteroffer, the success of that CO will be directly dependant on how long (as in offers back and forth) the original negotiations were. 

I had made an offer which was turned down and the counter offer came back a couple of weeks later, which I was set to accept.