Even if these poorly documented accounts are true, a fist-sized bump From Talk Origns
In fact, there are many cases where whales have been found with rudimentary atavistic hindlimbs in the wild (see Figure 2.2.1; for reviews see Berzin 1972, pp. 65-67 and Hall 1984, pp. 90-93). Hindlimbs have been found in baleen whales (Sleptsov 1939), humpback whales (Andrews 1921) and in many specimens of sperm whales (Abel 1908; Berzin 1972, p. 66; Nemoto 1963; Ogawa and Kamiya 1957; Zembskii and Berzin 1961). Most of these examples are of whales with femurs, tibia, and fibulae; however, some even include feet with complete digits.
Poorly-documented? Rare, but well-documented
Your source (AiG) said
Ignoring for the moment the purely anecdotal nature of the evidence, what is it that is being claimed? Sperm whales are massive — up to about 19m (62 feet) long. A 14 cm (5.5 inch) ‘bump’ on its side would look like an almost unnoticeable pimple. Inside the bump is a piece of bone, some 12.5 cm (5 inches) ‘long’. There is no evidence given of anything which could reasonably be called a ‘leg’.
Whereas TO said
These bones [referring to a photo] are the remnants of one of two symmetrical hind-limbs found protruding from the ventral side of a female humpback whale, captured by a whaling ship from the Kyuquot Station near the west coast of Vancouver Island, British Columbia, in July 1919.
...The museum's director, Francis Kermode, presented the bones to Roy Chapman Andrews from the American Museum of Natural History (AMNH) in New York. Andrews reported the findings, along with photographs of the whale from the whaling crew, in American Museum Novitates, the journal of the AMNH. Andrews identified in the remains a shrunken cartiliginous femur, tibia, tarsus, and metatarsal. Both legs initially were over four feet long and covered in normal blubber and skin
So, who to believe? The AMNH journal is not online, and I don't have access to a university library. But the fact is, the AiG article doesn't even address this particular claim, simply calling them all anecdotal. Personally, I don't consider things published in museum journals anecdotes.
Babinski documents a better case for whale atavisms than Wieland seems to think possible. Lots of drawings and photos. How is he doing that?
Wieland also says this:
Pakicetus was claimed to be a ‘walking whale’ — yet the type specimen consisted only of jaw and skull fragments.
For a long time, we had no post-cranial Pakicetus bones. Since 2000, we do.
Pakicetidae.
Some creationist sources are still running around pretending that we don't know what Paki looked like post-cranially. Creation science is somehow allowed to use old sources in misleading ways for some greater good.
Pakicetus is not the only such case among the cetaceans. See also: Ambulocetus Has No Pelvis and is Largely Incomplete? AiG strikes again!