I have to disagree with everyone that believes that limp-wristing does NOT exist. It most assuredly does.
BUT
Some guns are more suceptible than others and some guns aren't suceptible at all. It all comes down Newtons third law of motion and the law of Conservation of Energy.
In order for an automatic to fully cycle, extract the spent casing and rechamber a new round it must do several things. It must recoil far enough to extract the round, it must compress a spring with enough energy to return the slide, and it must come back forward with enough force to strip off a new round and chamber it.
Now, in order for the slide to move bcakwards there must be some resistance to the frame moving backwards. The slide will follow the path of least resistance, hopefully back along the frame. If the spring is very stiff then the frame requires bracing (by the shooter's grip). Otherwise the path of least resistance will be to move the entire gun, NOT cycling the slide back far enough to properly extract and feed.
Imagine for a moment that we have three springs for the same gun. Spring one is a VERY stiff spring. Spring Two is a normal spring, and spring three is a very weak spring.
Spring one will require the MOST bracing by the person holding the frame. If a person limp wrists the hold, the frame may move in his hand and not enough energy will get stored in the spring which can cause a failure of the slide to fully retract causing a failure to eject and/or a failure to feed.
Spring two, if properly designed, will require very little support by the user, but just enough spring to ensure that there is enough force left over to fully chamber the next round. Limp wristing may not cause any problems, or it may casue an occasional mis-feed depending on the weapon.
Spring three will NEVER have a problem ejecting as there is virtualy no resitance to the slide going to the rear. You could fire this gun hanging by a string and it would fully recoil. However it also will not chamber the next round as there will not be enough energy left in the spring to make the slide go forward. Also, all that excess energy that spring couldnt absorbe was slammed into the frame at max recoil, causing excessive wear and damage to the gun.
So Gun manufacturers have a challenge... design a slide/frame/recoil spring sufficiently strong to ensure reliable feeding and to buffer the shock of the recoil of the slide against the frame with out making it too stiff which can cause misfeeding or extraction problems.
Guns with heavier slides, lighter frames and stronger springs are more suceptible to a weak support of the frame causing malfunctions while guns with proportionaly heavier frame, lighter slide and lighter springs do not have to be supported so much (if at all) byt the user. Also, the resistance of the rails makes a difference too.
So in response about whether limp-wristing any given gun will cause malfunctions, I take the stance that it CAN, but more-so or less-so depending on the particular firearm. Some will do it all the time in a weak handed shooter and others will never do it.
FWIW, YMMV and any other disclaimer that you can think of!
J.T.