Locke saves Jack after the beach is bombed by Widmore's people

Jack is exhausted as he makes it to the beach after swimming from The Elizabeth. After he falls to his knees on the beach, he looks up to see Locke standing in front of him with about 8 others. Locke says "Sawyer took my boat, didn't he?" and Jack says yes.

Later, after the other group is captured a Zoe gives the order to fire on Locke, Jack hears the bombs mortars about to fall and screams "get down!"An explosion throw Jack and some of the others across the beach. Locke doesn't even budge at first. Look at the seventh photo below where he is calmly standing in the far left side of the screen as the explosions go off.

Jack is in a daze as he lays on the beach when Locke comes over to him, picks him up and carries him a short distance off the beach. He asks Jack if he's alright as explosions continue on the beach. Jack is on the verge of losing consciousness and doesn't respond. Locke says "Don't worry. It's gonna be okay. You're with me now."

Here's the question. Widmore knows that Locke is the smoke monster since he put up his own sonic fence, so did he actually think the bombs would have any effect on him? Why would he even bother bombing the beach unless it was just for show or he was trying destroy something else? Either way, it leaves Jack with Locke who will be in a difficult position once he wakes up.