If he backs into a ledge or a large hole.. make sure he isn't sharing it with a green moray!
Look before you grab.
Good advice above.
I catch about 50% of my bugs by hand. Sometimes they just back into a hole and you need to get them out. I've been chased by a green eel, but I've been bitten 3 times last season by the white spotted eels. It's part of the cost when you choose to stick your hand in the hole, even when looking before. A fight will invite company. We don't use any of the scuba gloves, not even the kevlar expensive gloves. They just won't stop the 3 rows of teeth grabbing your hand.
Infection is what you should be concerned about, not the bruise from the bite. We all have switch to the medical waste, needle stick-proof kevlar gloves. They are HexArmour 9003 gloves and cost about $20 on line. The gloves have a series of micro plates that you can take a hypodermic needle to and it won't punch thru. They also have a semi-smooth surface coating that you will allow you to slide your fingers down the antenna to grab the knuckles. Most other kevlar gloves have a fabric or fuzzy surface on the finger tips.
It still scares the crud out of you when a spotted bites your hand, but you won't lose it and the teeth won't puncture your skin. Get the gloves you'll save yourself alot of time over infections, some of which can be very serious.
On the subject of hand catching, I've been doing this for 15 years and have caught thousands of bugs. By hand catching them out of the hole, you will just chase them around the reef, knocking down fans, plants and destroying the reef. You also will consume double the amount of your air and not be monitoring it as closely{ie bent}. Remember you only find a honey hole full of bugs when you have 500psi left, any hunter will tell you that.
If you don't want to carry a net, then carry a Oceanus Green Looper. That's what all the good bug hunters carry. It's fast, slim, and allows you to keep swimming and looking for more bugs. Catching bugs is easy, Finding them is the hard part.