This is related to dangling modifiers. The sentence construction is often similar.
Grabbing his backpack from the table, he strolled down the road enjoying the sunshine.
Very long arms?
Taking a swig of his coffee, he carried on with his knitting.
To fix simultaneous actions, make sure your characters are doing one thing at a time, in logical sequence:
He grabbed his back pack from the table, then strolled down the road enjoying the sunshine.