Read the instructions?

Use a putty knife to finish the putty instead of fingers.

But, if he will not do it right, hire the pro.

Glazing windows is a dying art. Pull the points out and put them in correctly. Roll the glazing compound in you hands to get a long rope and place on the glass. Wet a small putty knife, place at a 30 degree angle and about 1/4" up the glass.
Run the knife down the glass. I am sure it will not go easily but if you keep the knife wet and keep going over the area you may end up with an exceptable outcome.

Use DAP33 glazing.

It needs to be worked to warm it up in cold weather, or kept in a cooler in hot weather for easier application.

If you get it to the correct temperature you do not need to wet the putty knife to strike it off cleanly.

Make sure there is enough putty at each edge to require striking off.
This makes sure that the putty is tight to the glass and the wood and has a uniform shape.
Corners usually require a little more work, but it should just be smoothing them off a little.

The other thing is to make sure you put a tiny bead on the opening before the glass goes in.
Most of it will squeeze out as the glass is gently pressed into position.

If you are not skilled at this it is always better to wet the putty knife. It can't hurt!

A picture says a thousand words. I learned some of my window glazing techniques by watch some YouTube videos. They're not always 100% "accurate" but it's better than guessing.

Guys that don't like to read instructions can maybe watch a video or 2. Tell your DH it's a sports video. ;-)

Here is a link that might be useful: How to glaze a window

Dying art indeed.

The surfaces have to be clean. If they're wood, prime them first. Oil paint is best since it retards the inevitable putty dry out.

Get a workable handful of the putty and massage/knead it to make it pliable. You want room temps or above.

Make a thin snake and apply to all the frame surface, called the "backbed" (probably regional)

Place the glass, mushing out the backbed to the edge of the frame. Set the points.

Take your handful of putty and use the thumb to place a dollop on the glass/frame, filling the fillet angle. Manipulate the hand to continuously feed putty to the thumb and repeat that step until you've gone around the glass. On large panes you'll need more than one handful.

Strike off with a knife (backbed too). If you're sloppy or slow, don't put contaminated putty back into your batch.

A scraper using a single-edge razor speeds pane clean up.

The job isn't complete 'til you paint, slightly over the putty onto the glass.

"If they're wood, prime them first."

Or treat them with BLO (boiled Linseed Oil).
Just paint it on, wait a few hours, then wipe off any that has not been absorbed by the wood.

Thanks everyone. DH is going to try and "fix" the window tomorrow. Will see how it turns out.

Our daughters were here today celebrating DH's birthday and gave him a few pointers. Maybe he will listen to them, I know he does not listen to his wife!!