No but if I watch a child (or an adult for that matter) for 20 hours and "look" for signs of disease with as many manifestations as Autism, I bet every subject would exhibit some of the signs. If at the same time the Parent is "pushing" for something to be "wrong" I'm betting that the child gets the Autism diagnosis.
You might find signs of cancer, malaria, and athlete's foot if you look long enough, too. Fortunately there are actual criteria involved.
The following is from the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM IV):
DIAGNOSTIC CRITERIA FOR 299.00 AUTISTIC DISORDER
A. A total of six (or more) items from (1), (2), and (3), with at
least two from (1), and one each from (2) and (3)
(1) qualitative impairment in social interaction, as manifested by at least two of the following:
a) marked impairments in the use of multiple nonverbal behaviors such as eye-to-eye gaze, facial expression, body posture, and gestures to regulate social interaction
b) failure to develop peer relationships appropriate to
developmental level
c) a lack of spontaneous seeking to share enjoyment, interests, or achievements with other people, (e.g., by a lack of showing,
bringing, or pointing out objects of interest to other people)
d) lack of social or emotional reciprocity ( note: in the
description, it gives the following as examples: not actively
participating in simple social play or games, preferring solitary
activities, or involving others in activities only as tools or
"mechanical" aids )
(2) qualitative impairments in communication as manifested by at least one of the following:
a) delay in, or total lack of, the development of spoken language
(not accompanied by an attempt to compensate through alternative modes of communication such as gesture or mime)
b) in individuals with adequate speech, marked impairment in the ability to initiate or sustain a conversation with others
c) stereotyped and repetitive use of language or idiosyncratic
language
d) lack of varied, spontaneous make-believe play or social
imitative play appropriate to developmental level
(3) restricted repetitive and stereotyped patterns of behavior,
interests and activities, as manifested by at least two of the
following:
a) encompassing preoccupation with one or more stereotyped and restricted patterns of interest that is abnormal either in
intensity or focus
b) apparently inflexible adherence to specific, nonfunctional
routines or rituals
c) stereotyped and repetitive motor mannerisms (e.g hand or finger flapping or twisting, or complex whole body movements)
d) persistent preoccupation with parts of objects
B. Delays or abnormal functioning in at least one of the following areas, with onset prior to age 3 years:
(1) social interaction
(2) language as used in social communication
(3) symbolic or imaginative play
C. The disturbance is not better accounted for by Rett's Disorder or Childhood Disintegrative Disorder